Email Signature Manager is failing to update signatures for users, and you see the below error in the Status Monitor and if you perform a Connectivity Test:
Unable to acquire the OAuth token to connect to Exchange Web Services
Email Signature Manager is not correctly renewing the authentication token that was generated when you authenticated credentials for Office 365. The authentication token by default expires after 90 days.
There are two possible solutions to this problem:
- Upgrade to Email Signature Manager version 9 or later.
- Open the Environment Configuration dialog and re-enter Office 365 credentials to generate a new authentication token.
Email Signature Manager, version 7 and 8