"Unauthorized" error when pushing images to ACR with Service Principal account

{% hint style="info" %} Affected versions: 2.13.0 to 2.16.0

Fixed in: 2.17.0 {% endhint %}

Issue Description

Users are unable to push images to the Azure Container Registry. The following error appears:

`Unauthorized: authentication required, visit  for more information."},"error":"unauthorized: authentication required, visit  for more information."}`

Cause

This issue is the result of using Service Principal accounts in the Azure Container Registry configuration in Portainer.

Workaround

You will need to configure your Azure Container Registry using the Access Key (Admin) account.