AADSTS9002313 “Invalid request” during Exchange Online authentication after upgrading MNE (4384275)

After upgrading MNE, all migration jobs fail while authenticating to Exchange Online.

The migration log records the following error:

System.AggregateException: One or more errors occurred.
Microsoft.Identity.Client.MsalUiRequiredException:
AADSTS9002313: Invalid request. Request is malformed or invalid.

The Windows user profile running MNE contains a stale or invalid Microsoft Authentication Library token in its temporary-file cache.

MNE attempts to reuse the cached token, but Microsoft Entra ID rejects the authentication request. The MsalUiRequiredException indicates that interactive authentication is required, but the existing cached authentication context prevents MNE from completing that process correctly.

Perform the following steps on the MNE migration server.

1. Close the MNE console, the Data Migration Wizard, Outlook, and any other Office applications.
2. While signed in as the Windows administrator normally used to run MNE, press Windows + R.
3. Enter the following path and click OK:

%TEMP%

4. Delete the following files if they are present:

MNEUnifiedTokenCache.dat
MNETokenCache.dat

5. Sign out of Windows.
6. Sign in to the same MNE migration server using a different Windows administrator account.
7. Start MNE and authenticate to Exchange Online.
8. Confirm that the following error is no longer generated:

AADSTS9002313: Invalid request. Request is malformed or invalid.

9. Close MNE and sign out of the secondary administrator account.
10. Sign back in using the Windows administrator account normally used to run MNE.
11. Start MNE and complete the Exchange Online authentication when prompted.
12. Rerun the Data Migration Wizard and confirm that the migration proceeds successfully.