docs/mobile-app-guide/first-steps/login-troubleshooting/README.md
If you’re having trouble logging into the OpenProject Mobile App, the following sections will help you identify and resolve the most common issues.
Symptom:
You see a browser error such as “The site can't be reached. The server address could not be found”.
Cause:
The URL you entered may be incorrect, inaccessible, or not using HTTPS.
Possible Solution:
https://yourcompany.openproject.com).Symptom:
Login fails with a browser error such as _“An authorization error has occurred. The client is not authorized to perform this request using this method.”, or you are redirected back to the login screen without authentication.
Cause:
The mobile app uses OAuth 2.0 for secure authentication. If the built-in OAuth applications are not enabled in your instance, the app cannot log you in.
Possible Solution:
{BASE_URL}/admin/oauth/applicationsSymptom:
You know that your instance is running not on the minimum supported version, OpenProject 17.0.0, and the login fails with a browser error such as “An authorization error has occurred. The client is not authorized to perform this request using this method.”.
Cause:
The OpenProject Mobile App requires your instance to be on OpenProject version 17.0.0 or higher.
If your instance is running an older version, OAuth authentication may be disabled by default.
Possible Solution:
{BASE_URL}/admin/settings/experimental{BASE_URL}/admin/oauth/applications, once enabled the users can log in via the mobile app.[!NOTE] Upgrading to the latest OpenProject version is recommended for the best compatibility and security.
Symptom:
You receive a browser error message such as “Secure connection failed. Untrusted certificate”.
Cause:
Your OpenProject instance must use a valid, signed SSL certificate (HTTPS). Self-signed certificates or expired certificates are not supported.
Possible Solution:
Symptom:
You see “Invalid username or password” when logging in.
Cause:
Your login credentials are incorrect or have been changed.
Possible Solution:
Symptom:
Login attempts fail with no clear error message.
Cause:
Your on-premises OpenProject instance may have API access disabled, preventing the mobile app from connecting.
Possible Solution:
Administration → System settings → APISymptom:
You receive a browser error message such as “Secure connection failed. Untrusted certificate”.
Cause:
The mobile app only supports secure connections via HTTPS.
Possible Solution:
Symptom:
Login attempts time out or fail when using certain networks with an error such as “Login time out. Check your network”.
Cause:
Corporate or restricted networks may block outbound requests to your OpenProject instance or authentication endpoints.
Possible Solution: