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Configure Microsoft Intune Mobile Application Management (MAM)

docs/main/deployment-guide/mobile/configure-microsoft-intune-mam.mdx

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<PlanAvailability slug="entry-adv" />

You can configure the Mattermost Mobile App on iOS to enforce Microsoft Intune App Protection Policies (MAM) so organizational data remains protected on Bring Your Own Device (BYOD) and mixed-use devices without requiring device enrollment (MDM).

This guide documents the required configuration to enable Intune MAM successfully on iOS.

Read This First

Intune MAM enforcement in Mattermost is identity-based and applies only to the sign-in method selected as the enforced Auth Provider in System Console > Environment > Mobile Security.

  • The enforced authentication provider must resolve users using Azure AD objectId (IdAttribute = objectId).
  • MSAL access tokens must include the oid claim, and it must match the same Azure AD objectId (confirm identity alignment: objectId ↔ oid).

If Intune MAM enrollment fails due to a technical error, the affected Mattermost server is removed from the mobile app and cached data for that server is wiped from the device.

Unsupported Scenarios

This guide doesn't apply when:

  • You require Intune MAM on Android devices.
  • You want Intune MAM enforcement for a sign-in method not backed by Microsoft Entra ID.
  • The enforced authentication provider cannot resolve users to Azure AD objectId.
  • You require a rollout model where users can bypass or defer Intune MAM for the enforced sign-in method.

Other authentication methods, such as guest access, may still be enabled separately, but they aren't evaluated by Intune MAM.

Prerequisites

Confirm the following before continuing:

  • Microsoft Entra ID is used for authentication.
  • You can commit to Azure AD objectId as the authoritative identity.
  • Mattermost Enterprise Advanced licensing is available for the server.
  • Target users are licensed for Microsoft Intune.
  • You can register applications and grant tenant-wide admin consent in Microsoft Entra.
  • If enforcing Intune MAM on SAML, users already exist in Mattermost (mobile sign-in does not create users for SAML).
<Note>

In this guide, OpenID Connect (OIDC) refers to the Microsoft Entra sign-in method used by the Mattermost Mobile App via MSAL.

</Note>

Configuration Overview

Successful Intune MAM enforcement requires coordinated configuration across:

  • Microsoft Entra ID – app registration, scope, API permissions, admin consent
  • Microsoft Intune – iOS App Protection Policies
  • Mattermost Server – MAM enablement and provider selection
  • Mattermost Mobile App (iOS) – enrollment and enforcement

Complete the steps below in order.

Setup Summary

  1. Confirm identity requirements and alignment (objectId ↔ oid).
  2. Configure Microsoft Entra (server-referenced application).
  3. Configure Intune App Protection Policies.
  4. Enable Intune MAM in Mattermost and select the enforced provider.
  5. Deploy the official Mattermost iOS app.
  6. Validate enrollment and enforcement.

Values You’ll Need Later

Capture these during setup:

<table style={{width: '99%'}}> <colgroup> <col style={{width: '23%'}} /> <col style={{width: '30%'}} /> <col style={{width: '46%'}} /> </colgroup> <thead> <tr> <th>Value</th> <th>Where to get it</th> <th>Where you use it</th> </tr> </thead> <tbody> <tr> <td>Directory (tenant) ID</td> <td>Entra app registration overview</td> <td>Mattermost System Console</td> </tr> <tr> <td>Application (client) ID</td> <td>Entra app registration overview</td> <td>Mattermost System Console</td> </tr> <tr> <td>Application ID URI</td> <td>Entra app &gt; Expose an API</td> <td>Used to form the <code>api://&lt;APPLICATION-ID&gt;/login.mattermost</code> scope reference in Authorized client applications</td> </tr> <tr> <td><code>login.mattermost</code> scope</td> <td>Entra app &gt; Expose an API</td> <td>Authorized client applications</td> </tr> <tr> <td>Mobile client application ID</td> <td>Provided by Mattermost</td> <td>Entra app &gt; Authorized client applications</td> </tr> <tr> <td>iOS bundle IDs (prod/beta)</td> <td>This guide</td> <td>Intune App Protection Policies</td> </tr> </tbody> </table>

Step 1: Identity Configuration for Intune MAM

<div id="step-1-identity-configuration-for-intune-mam">

This step defines the required identity model for the authentication provider selected for Intune MAM enforcement.

</div>

Required Identity Model

Microsoft Intune MAM for Mattermost requires Azure AD objectId as the authoritative user identifier. The following is non-negotiable.

  • IdAttribute must equal objectId for the enforced provider.
  • MSAL access tokens must include the oid claim.
  • Confirm identity alignment (objectId ↔ oid) before enabling Intune MAM.

Confirm Identity Alignment (objectId ↔ oid)

<div id="identity-alignment-objectid-oid">

For the same user, the following values must match:

</div>
  • Azure AD objectId
  • MSAL access token oid claim
  • SAML objectidentifier (if applicable)
  • LDAP msDS-aadObjectId (if applicable)

Any mismatch prevents enrollment.

Identity Enforcement by Authentication Method

OIDC (Mobile sign-in via MSAL)

  • Mattermost uses the MSAL access token for identity and enrollment.
  • Confirm identity alignment (objectId ↔ oid).

SAML (Entra-backed)

  • SamlSettings.IdAttribute must map to objectidentifier.
  • Email, UPN, and immutableID aren't supported.
  • Users must already exist in Mattermost before mobile sign-in.

LDAP (Entra ID Domain Services)

  • Use msDS-aadObjectId.
  • Do not use objectGUID.

Runtime Enforcement Behavior

When Intune MAM is enabled for a provider:

  • Enforcement occurs during active sessions, not only at login.
  • If Intune MAM becomes newly required due to policy, licensing, or configuration changes, enrollment may be triggered immediately.
  • Users can’t bypass enforcement for the enforced provider.

Pre-flight Checklist

  • Licensed Intune test user available
  • Ability to grant tenant-wide admin consent
  • Enforced provider identified (OIDC or SAML)
  • IdAttribute = objectId configured
  • Identity alignment verified (objectId ↔ oid)
  • Official Mattermost iOS app deployed
  • Target bundle IDs known: com.mattermost.rn (Production), com.mattermost.rnbeta (Beta)

Step 2: Microsoft Entra Configuration for Intune MAM

<div id="step-2-microsoft-entra-configuration-for-intune-mam">

You register a single-tenant Microsoft Entra application that is referenced by Mattermost Server. This application validates MSAL access tokens and supports Intune MAM enrollment.

</div>

You don't register the Mattermost Mobile app itself. Redirect URI configuration isn't required.

Entra Application Registration

  1. Go to Identity > Applications > App registrations
  2. Select New registration
  3. Configure:
    • Name: Mattermost Mobile (Intune MAM)
    • Supported account types: Single tenant
  4. Register the app
  5. Copy:
    • Application (client) ID
    • Directory (tenant) ID

Expose the API and Create the Scope

  1. Go to Expose an API
  2. Confirm Application ID URI is set (for example, api://<APPLICATION-ID>)
  3. Add a scope named login.mattermost
  4. Save your changes.

Authorize the Official Mobile Client

Authorize the official Mattermost Mobile client application ID (provided by Mattermost) to request the login.mattermost scope.

  1. In the Entra app registration, go to Expose an API.
  2. Under Authorized client applications, select Add a client application.
  3. Add the official Mattermost Mobile client application ID (provided by Mattermost) as:
  • Beta: 64e9952b-20eb-46dc-92ad-99089ed24903
  • Production: 9ac649f1-4f77-44d6-9792-b2f54ab3c9a7
  1. Authorize the api://<APPLICATION-ID>/login.mattermost scope.
  2. Save your changes.
<div id="api-permissions-admin-consent">
  1. Go to API permissions.
  2. Select Add a permission.
  3. Add the following Microsoft Graph delegated permissions:
    • Microsoft Graph → email (Delegated)
    • Microsoft Graph → profile (Delegated)
  4. Select Grant admin consent for your tenant.
</div>

These are the permissions the customer admin must grant for the Entra application referenced by Mattermost Server.

If these permissions are missing or lack tenant-wide admin consent, enrollment can fail with an Entra permissions/admin-consent error (for example, AADSTS650057) or a user-visible Consent Denied message during first sign-in.

Configure MSAL tokens and required claims

Before enabling Intune MAM, ensure the Entra app registration issues access tokens with the claims Mattermost expects during mobile sign-in.

  1. In the Entra app registration, go to Token configuration.
  2. Select Add optional claim.
  3. Under Token type, select Access.
  4. Add the following optional claims:
    • email
    • family_name
    • given_name
    • preferred_username
    • upn
  5. Save your changes.
<Note>

Mattermost Intune MAM enforcement uses the MSAL access token. If required claims are missing, sign-in and/or enrollment may fail.

</Note>

Enable MSAL v2 access tokens

  1. Open the app Manifest.
  2. Set the token version to 2:
    • If your manifest shows api.requestedAccessTokenVersion, set it to 2.
    • Otherwise set accessTokenAcceptedVersion to 2.
  3. Save your changes.

Step 3: Configure Intune App Protection Policies

  1. Go to Intune admin center > Apps > App protection policies.
  2. Create a policy:
    • Platform: iOS/iPadOS
    • Targeted app: Managed apps
  3. Add the Mattermost app by bundle ID:
    • com.mattermost.rn (Production)
    • com.mattermost.rnbeta (Beta)
  4. Configure protection settings.
  5. Assign to Entra ID user groups.
  6. Save your changes.

Separate policies are required for Production and Beta apps.

Step 4: Configure Mattermost Server for Intune MAM

<div id="step-4-configure-mattermost-server-for-intune-mam">
  1. Go to System Console > Environment > Mobile Security
  2. Set Enable Microsoft Intune MAM to True
  3. Select Auth Provider:
    • OpenID Connect (Entra-backed)
    • SAML 2.0 (Entra-backed)
  4. Enter:
    • Tenant ID
    • Application (Client) ID
  5. Save your changes.
</div>

The enforced provider must resolve identity using IdAttribute = objectId.

Step 5: Deploy the Mattermost iOS App

Download and install the official Mattermost iOS app using:

  • Apple App Store (Production)
  • TestFlight (Beta)

Wrapped, re-signed, or privately distributed apps aren't supported.

Step 6: Validate Enrollment

Validate with a licensed test user on iOS.

Confirm:

  • Enrollment completes successfully
  • Enforcement applies at sign-in and mid-session
  • Identity alignment is correct (objectId ↔ oid)

Expected Behavior During Mobile Sign-In

  1. User signs in via MSAL.
  2. Mattermost validates the access token.
  3. Intune MAM enrollment is triggered.
  4. App Protection Policies are applied.

If enrollment is required but cannot complete, access is blocked until enrollment succeeds.

Troubleshooting

<div id="troubleshooting">

Most failures are caused by:

</div>
  • Identity mismatch (objectId ↔ oid)
  • IdAttribute not set to objectId
  • Missing Entra API permissions or admin consent
  • App Protection Policy not targeting the user or app
  • Unsupported client or platform

Quick Diagnostics

  1. Confirm identity alignment (objectId ↔ oid).
  2. Confirm IdAttribute = objectId.
  3. Confirm Entra permissions and admin consent.
  4. Confirm Auth Provider selection.
  5. Confirm Intune policy targeting.

If the user declines enrollment, retry is allowed.

Intune MAM Errors

The errors below may occur during mobile sign-in or when Intune MAM enforcement is triggered mid-session. Some errors are shown in the Mattermost Mobile App, while others are silent and must be diagnosed using Mattermost server logs.

<Note>

In the table below, Fallback: Web SSO means the mobile app uses the non-Intune version of the configured sign-in method (SAML or OpenID Connect) as if Intune MAM were not enabled.

</Note> <style> /* Compact, scannable 3-column table with full inline metadata and strong grid lines */ .mm-intune-errors &#123; width: 100%; border-collapse: collapse; table-layout: fixed; /* prevents horizontal scrolling */ margin: 0.75rem 0 1rem 0; font-size: 0.95rem; line-height: 1.35; border: 1px solid #b3b3b3; &#125; .mm-intune-errors th, .mm-intune-errors td &#123; padding: 0.6rem 0.7rem; vertical-align: top; border: 1px solid #b3b3b3; overflow-wrap: anywhere; word-break: break-word; white-space: normal; background: transparent; color: inherit; &#125; /* Light mode header: explicit contrast */ .mm-intune-errors th &#123; font-weight: 600; text-align: left; background-color: #f2f2f2; color: #111111; &#125; /* Strong row separation */ .mm-intune-errors tbody tr + tr td &#123; border-top-width: 2px; &#125; .mm-intune-errors code &#123; font-size: 0.9em; white-space: normal; padding: 0.1em 0.25em; border-radius: 4px; background: rgba(0, 0, 0, 0.08); &#125; .mm-intune-errors .meta &#123; opacity: 0.92; font-size: 0.92em; margin-top: 0.35rem; &#125; .mm-intune-errors .meta div &#123; margin: 0.08rem 0; &#125; .mm-intune-errors .label &#123; font-weight: 600; &#125; /* Dark mode override */ @media (prefers-color-scheme: dark) &#123; .mm-intune-errors, .mm-intune-errors th, .mm-intune-errors td &#123; border-color: #666; &#125; .mm-intune-errors th &#123; background-color: #2a2a2a; color: #ffffff; &#125; .mm-intune-errors code &#123; background: rgba(255, 255, 255, 0.14); &#125; .mm-intune-errors .meta &#123; opacity: 0.9; &#125; &#125; </style> <table class="mm-intune-errors" aria-label="Microsoft Intune MAM errors and admin remediation steps"> <thead> <tr> <th style={{width: '30%'}}>Error</th> <th style={{width: '22%'}}>Meaning</th> <th style={{width: '48%'}}>Admin cause &amp; next step</th> </tr> </thead> <tbody> <tr> <td> <strong>Enrollment Failed</strong> <div class="meta"> <div><span class="label">Error ID:</span> <code>(varies)</code></div> <div><span class="label">HTTP:</span> <code>(varies)</code></div> <div><span class="label">Scenario:</span> Enrollment failed (technical)</div> <div><span class="label">User message:</span> "Enrollment Failed"</div> <div><span class="label">Retry:</span> No</div> <div><span class="label">Fallback:</span> None</div> </div> </td> <td> Intune MAM enrollment failed due to a technical error. </td> <td> <span class="label">Cause:</span> Enrollment could not be completed due to a technical failure (MSAL error, Intune enrollment API failure, identity mismatch, or missing Entra permissions). 
    <span class="label">Behavior:</span> The server is removed immediately and there is no retry option; cached data for that server is wiped.

    <span class="label">Next step:</span> Fix the underlying issue, then have the user re-add the server in the mobile app.

    <span class="label">Admin checks:</span> Verify <code>IdAttribute = objectId</code>; confirm identity alignment (<code>objectId ↔ oid</code>); confirm tenant-wide admin consent; confirm App Protection Policy targets the user and the correct iOS bundle ID.
  </td>
</tr>
<tr>
  <td>
    <strong>Enrollment Declined</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>(varies)</code></div>
      <div><span class="label">HTTP:</span> <code>(varies)</code></div>
      <div><span class="label">Scenario:</span> User declined enrollment</div>
      <div><span class="label">User message:</span> "Enrollment Declined"</div>
      <div><span class="label">Retry:</span> Yes</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    The user declined Intune MAM enrollment.
  </td>
  <td>
    <span class="label">Cause:</span> The user canceled the enrollment prompt.

    <span class="label">Behavior:</span> A <strong>Retry</strong> option is shown; no server data is removed unless a later technical enrollment failure occurs.

    <span class="label">Next step:</span> Instruct the user to retry enrollment when ready.
  </td>
</tr>
<tr>
  <td>
    <strong>Consent Denied</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>(varies)</code></div>
      <div><span class="label">HTTP:</span> <code>(varies)</code></div>
      <div><span class="label">Scenario:</span> Admin consent missing (first login)</div>
      <div><span class="label">User message:</span> "You denied consent for Intune management. The affected accounts have been unenrolled and signed out."</div>
      <div><span class="label">Retry:</span> Yes (after admin consent)</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    Enrollment cannot complete because required Entra app permissions don’t have tenant-wide admin consent.
  </td>
  <td>
    <span class="label">Cause:</span> Tenant-wide admin consent has not been granted for the required delegated permissions on the Entra app registration configured in Mattermost Server.

    <span class="label">Behavior:</span> The message may appear as if the user denied consent, but the underlying issue is missing admin consent.

    <span class="label">Next step:</span> In Microsoft Entra, grant tenant-wide admin consent for Microsoft Graph delegated permissions <code>email</code> and <code>profile</code> on the same Entra app registration configured in Mattermost, then have the user retry mobile sign-in.
  </td>
</tr>
<tr>
  <td>
    <strong>(silent)</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>api.user.login_by_intune.not_available.app_error</code></div>
      <div><span class="label">HTTP:</span> 501</div>
      <div><span class="label">Scenario:</span> Enterprise not compiled</div>
      <div><span class="label">User message:</span> (silent)</div>
      <div><span class="label">Retry:</span> No</div>
      <div><span class="label">Fallback:</span> Standard SSO (non-Intune)</div>
    </div>
  </td>
  <td>
    Intune MAM login is not available on this server.
  </td>
  <td>
    <span class="label">Cause:</span> The server does not support Intune MAM (feature not available in this build or not enabled for the deployment).

    <span class="label">Next step:</span> Confirm the server build includes Intune MAM support and the deployment is licensed for Enterprise Advanced.

    <span class="label">User guidance:</span> Have the user sign in via web/desktop using the standard (non-Intune) SSO flow for their provider (SAML or OpenID Connect) while the server is updated or configuration is corrected.
  </td>
</tr>
<tr>
  <td>
    <strong>(silent)</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>api.user.login_by_intune.not_configured.app_error</code></div>
      <div><span class="label">HTTP:</span> 400</div>
      <div><span class="label">Scenario:</span> Intune not configured</div>
      <div><span class="label">User message:</span> (silent)</div>
      <div><span class="label">Retry:</span> No</div>
      <div><span class="label">Fallback:</span> Standard SSO (non-Intune)</div>
    </div>
  </td>
  <td>
    Intune MAM is enabled for the org but not configured on the server.
  </td>
  <td>
    <span class="label">Cause:</span> Intune MAM isn't fully configured in <strong>System Console &gt; Environment &gt; Mobile Security</strong>.

    <span class="label">Next step:</span> Enable Microsoft Intune MAM and ensure <strong>Tenant ID</strong>, <strong>Application (Client) ID</strong>, and <strong>Auth Provider</strong> are set correctly.

    <span class="label">Admin checks:</span> Confirm the selected auth provider is Entra-backed and required permissions/admin consent have been granted for the Entra app registration.

    <span class="label">User guidance:</span> Have the user sign in via web/desktop using the standard (non-Intune) SSO flow for their provider (SAML or OpenID Connect) while the server is updated or configuration is corrected.
  </td>
</tr>
<tr>
  <td>
    <strong>Bot accounts cannot sign in using this method.</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>api.user.login_by_intune.bot_login_forbidden.app_error</code></div>
      <div><span class="label">HTTP:</span> 403</div>
      <div><span class="label">Scenario:</span> Bot tried to login</div>
      <div><span class="label">User message:</span> "Bot accounts cannot sign in using this method."</div>
      <div><span class="label">Retry:</span> No</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    The account cannot use Intune MAM sign-in.
  </td>
  <td>
    <span class="label">Cause:</span> Bot accounts are not allowed to authenticate via Intune MAM.

    <span class="label">Next step:</span> Use a human user account for Intune MAM enrollment and access.
  </td>
</tr>
<tr>
  <td>
    <strong>Your account has been deactivated. Please contact your administrator.</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>api.user.login_by_intune.account_locked.app_error</code></div>
      <div><span class="label">HTTP:</span> 409</div>
      <div><span class="label">Scenario:</span> User deleted/disabled</div>
      <div><span class="label">User message:</span> "Your account has been deactivated. Please contact your administrator."</div>
      <div><span class="label">Retry:</span> No</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    The account is not permitted to sign in.
  </td>
  <td>
    <span class="label">Cause:</span> The user is deleted, disabled, or locked in Mattermost.

    <span class="label">Next step:</span> Re-enable or restore the user account in Mattermost, then retry sign-in and enrollment.
  </td>
</tr>
<tr>
  <td>
    <strong>(silent)</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>ent.intune.login.not_configured.app_error</code></div>
      <div><span class="label">HTTP:</span> 403</div>
      <div><span class="label">Scenario:</span> IsConfigured() = false</div>
      <div><span class="label">User message:</span> (silent)</div>
      <div><span class="label">Retry:</span> No</div>
      <div><span class="label">Fallback:</span> Standard SSO (non-Intune)</div>
    </div>
  </td>
  <td>
    Intune MAM is not configured for the current sign-in path.
  </td>
  <td>
    <span class="label">Cause:</span> Intune MAM isn't configured for the requested authentication path (configuration incomplete or mismatched provider selection).

    <span class="label">Next step:</span> Confirm Intune MAM is enabled and configured, and the selected <strong>Auth Provider</strong> matches how users authenticate (OIDC vs SAML).

    <span class="label">User guidance:</span> Have the user sign in via web/desktop using the standard (non-Intune) SSO flow for their provider (SAML or OpenID Connect) while the server is updated or configuration is corrected.
  </td>
</tr>
<tr>
  <td>
    <strong>We couldn't complete your sign in. Please try again.</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>ent.intune.login.extract_auth_data.app_error</code></div>
      <div><span class="label">HTTP:</span> 400</div>
      <div><span class="label">Scenario:</span> IdAttribute mapping failed</div>
      <div><span class="label">User message:</span> "We couldn't complete your sign in. Please try again."</div>
      <div><span class="label">Retry:</span> Yes (1x)</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    Identity mapping failed during sign-in.
  </td>
  <td>
    <span class="label">Cause:</span> The server couldn’t extract or map the identity attribute required for Intune MAM (commonly <code>IdAttribute</code> is misconfigured or the token isn't MSAL v2).

    <span class="label">Next step:</span> Ensure <code>IdAttribute = objectId</code>, then confirm identity alignment (<code>objectId ↔ oid</code>). Verify the Entra app issues v2 tokens (<code>accessTokenAcceptedVersion = 2</code>).
  </td>
</tr>
<tr>
  <td>
    <strong>Your account isn't fully set up yet. Please sign in to Mattermost via the web or desktop app first.</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>ent.intune.login.account_not_found.app_error</code></div>
      <div><span class="label">HTTP:</span> 428</div>
      <div><span class="label">Scenario:</span> SAML user account not found</div>
      <div><span class="label">User message:</span> "Your account isn't fully set up yet. Please sign in to Mattermost via the web or desktop app first."</div>
      <div><span class="label">Retry:</span> No</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    The user does not exist in Mattermost for SAML-based sign-in.
  </td>
  <td>
    <span class="label">Cause:</span> When SAML is the selected provider for Intune MAM enforcement, mobile sign-in cannot create a new user.

    <span class="label">Next step:</span> Have the user sign in once via the web or desktop app to provision the account, then retry mobile sign-in.

    <span class="label">Admin checks:</span> Ensure provisioning is in place (web/desktop first sign-in, LDAP sync, or another provisioning method).
  </td>
</tr>
<tr>
  <td>
    <strong>We couldn't verify your sign in. Please try again.</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>ent.intune.validate_token.invalid_token.app_error</code></div>
      <div><span class="label">HTTP:</span> 400</div>
      <div><span class="label">Scenario:</span> Token validation failed</div>
      <div><span class="label">User message:</span> "We couldn't verify your sign in. Please try again."</div>
      <div><span class="label">Retry:</span> Yes (1x)</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    The access token could not be validated.
  </td>
  <td>
    <span class="label">Cause:</span> Token validation failed (token malformed, wrong issuer/audience, missing permissions, or Entra configuration mismatch).

    <span class="label">Next step:</span> Verify the configured <strong>Tenant ID</strong> and <strong>Application (Client) ID</strong> match the Entra app registration referenced by Mattermost Server. Confirm tenant-wide admin consent has been granted for Microsoft Graph delegated permissions <code>email</code> and <code>profile</code> on that same app registration. Then confirm identity alignment (<code>objectId ↔ oid</code>) for the affected user.

    <span class="label">Admin checks:</span> Confirm v2 tokens (<code>accessTokenAcceptedVersion = 2</code>) and that Microsoft Graph delegated permissions <code>email</code> and <code>profile</code> have tenant-wide admin consent.
  </td>
</tr>
<tr>
  <td>
    <strong>Your sign in session has expired. Please try signing in again.</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>ent.intune.validate_token.token_expired.app_error</code></div>
      <div><span class="label">HTTP:</span> 400</div>
      <div><span class="label">Scenario:</span> Token expired</div>
      <div><span class="label">User message:</span> "Your sign in session has expired. Please try signing in again."</div>
      <div><span class="label">Retry:</span> Yes (1x)</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    The authentication session expired before enrollment completed.
  </td>
  <td>
    <span class="label">Cause:</span> The access token or interactive session expired during sign-in/enrollment.

    <span class="label">Next step:</span> Have the user sign in again and complete enrollment promptly.

    <span class="label">Admin checks:</span> If repeated, confirm the device can reach Entra/Intune endpoints during enrollment and prompts aren't being blocked.
  </td>
</tr>
<tr>
  <td>
    <strong>We couldn't complete your sign in. Please contact your IT administrator.</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>ent.intune.validate_token.missing_claims.app_error</code></div>
      <div><span class="label">HTTP:</span> 400</div>
      <div><span class="label">Scenario:</span> Required claims missing</div>
      <div><span class="label">User message:</span> "We couldn't complete your sign in. Please contact your IT administrator."</div>
      <div><span class="label">Retry:</span> No</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    The access token is missing required claims for sign-in and enrollment.
  </td>
  <td>
    <span class="label">Cause:</span> Required claims are missing from the MSAL access token (most commonly <code>oid</code>, or optional claims required by Mattermost).

    <span class="label">Next step:</span> Confirm MSAL v2 access tokens are issued (<code>accessTokenAcceptedVersion = 2</code>) and the token includes <code>oid</code>. In the Entra app registration, go to <strong>Token configuration</strong> and ensure optional claims are added for the <strong>Access</strong> token: <code>email</code>, <code>family_name</code>, <code>given_name</code>, <code>preferred_username</code>, and <code>upn</code>. Confirm the enforced provider uses <code>IdAttribute = objectId</code>, then verify identity alignment (<code>objectId ↔ oid</code>).
  </td>
</tr>
<tr>
  <td>
    <strong>There was a configuration issue. Please contact your IT administrator.</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>ent.intune.validate_token.invalid_tenant_id.app_error</code></div>
      <div><span class="label">HTTP:</span> 400</div>
      <div><span class="label">Scenario:</span> Token tenant ≠ configured tenant</div>
      <div><span class="label">User message:</span> "There was a configuration issue. Please contact your IT administrator."</div>
      <div><span class="label">Retry:</span> No</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    The token tenant does not match the configured tenant.
  </td>
  <td>
    <span class="label">Cause:</span> The token was issued by a different tenant than the one configured in Mattermost.

    <span class="label">Next step:</span> Verify the <strong>Tenant ID</strong> configured in <strong>System Console &gt; Environment &gt; Mobile Security</strong> matches the Entra tenant issuing MSAL tokens for the user.
  </td>
</tr>
<tr>
  <td>
    <strong>AADSTS650057</strong>

    <span class="meta">(invalid_resource)</span>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>(AADSTS650057)</code></div>
      <div><span class="label">HTTP:</span> <code>(varies)</code></div>
      <div><span class="label">Scenario:</span> invalid_resource</div>
      <div><span class="label">User message:</span> (MSAL/Entra error)</div>
      <div><span class="label">Retry:</span> No (until fixed)</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    The Entra app configuration is missing required permissions and/or admin consent.
  </td>
  <td>
    <span class="label">Cause:</span> Required Intune MAM API permissions are missing or do not have tenant-wide admin consent.

    <span class="label">Next step:</span> In the Microsoft Entra admin center, go to <strong>Enterprise applications</strong> (not App registrations), search for <strong>Mattermost Mobile</strong> / <strong>Mattermost Mobile Beta</strong>, then open <strong>Permissions</strong> and add/grant admin consent for the Intune MAM permissions (for example, <code>https://msmamservice.api.application/.default</code> and <strong>Microsoft Mobile Application Management</strong> → <code>user_impersonation</code> (Delegated)). Then have the user retry sign-in.
  </td>
</tr>
<tr>
  <td>
    <strong>NotLicensed</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>(NotLicensed)</code></div>
      <div><span class="label">HTTP:</span> <code>(varies)</code></div>
      <div><span class="label">Scenario:</span> License missing or inactive</div>
      <div><span class="label">User message:</span> (varies)</div>
      <div><span class="label">Retry:</span> No</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    The server is not licensed for Intune MAM enforcement.
  </td>
  <td>
    <span class="label">Cause:</span> Enterprise Advanced licensing is missing or not applied to the server.

    <span class="label">Next step:</span> Apply an Enterprise Advanced license to the server and confirm the license is active, then retry.
  </td>
</tr>
<tr>
  <td>
    <strong>HTTP 403 Forbidden</strong>
    <div class="meta">
      <div><span class="label">Error ID:</span> <code>(HTTP 403)</code></div>
      <div><span class="label">HTTP:</span> 403</div>
      <div><span class="label">Scenario:</span> Server-side access blocked</div>
      <div><span class="label">User message:</span> (varies)</div>
      <div><span class="label">Retry:</span> No</div>
      <div><span class="label">Fallback:</span> None</div>
    </div>
  </td>
  <td>
    Server-side access is blocked by a gating condition.
  </td>
  <td>
    <span class="label">Cause:</span> A server gating condition is preventing enrollment (not an Intune service failure).

    <span class="label">Next step:</span> Verify Enterprise Advanced licensing, Intune MAM is enabled, <strong>Auth Provider</strong> selection matches how users authenticate, configured <strong>Tenant ID</strong> and <strong>Application (Client) ID</strong> are correct, and tenant-wide admin consent is granted. Then confirm identity alignment (<code>objectId ↔ oid</code>) and Intune App Protection Policy targeting for the correct iOS bundle ID.
  </td>
</tr>
</tbody> </table>

If a user’s first mobile sign-in fails with Consent Denied or:

You denied consent for Intune management. The affected accounts have been unenrolled and signed out.

Treat this as missing tenant-wide admin consent for the Entra app registration referenced by Mattermost Server. See the Consent Denied entry in the Intune MAM Errors table above for remediation steps.

To resolve this:

  1. In the Microsoft Entra admin center, go to Enterprise applications.
  2. Search for Mattermost Mobile or Mattermost Mobile Beta.
  3. Go to Permissions and add/grant tenant-wide admin consent for the Intune MAM permissions (for example, https://msmamservice.api.application/.default and Microsoft Mobile Application Management → user_impersonation (Delegated)).
  4. Have the user retry mobile sign-in.

Rollout and Recovery Guidance

  • Pilot with a small group first
  • Validate identity alignment before broad rollout
  • Expect enforcement to occur mid-session if requirements change