"Access Denied", or user is repeatedly prompted for credentials when connecting to Microsoft 365

Problem

When users try to access a Microsoft 365 resource from a rich client application such as Microsoft Outlook or Microsoft Lync, one of the following symptoms occurs:

  • Users are repeatedly prompted to enter their credentials.
  • Users receive the Access Denied error.

Solution

Tip

To diagnose and automatically fix several common Office sign-in issues, you can download and run the Microsoft Support and Recovery Assistant.

To fix this problem, reset the user's password. To do this, follow these steps:

  1. Open a web browser, browse to the Microsoft 365 portal (https://portal.office.com), and then sign in by using the user's expired credentials.
  2. When you're prompted, enter a new Microsoft 365 password for the user. Make sure that the password meets the criteria for Microsoft 365.

References

For information about related issues, see the following articles:

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