Outlook Actionable Messages error 401 or 500 while approving from Outlook mailboxIssue Outlook Actionable Messages is a feature that you might have installed with the plugin id: 'sn_ms_oam' Most probably after an upgrade, users are unable to approve the requests. (This was seen in the upgrade to Vancouver, however, this is relevant to any upgrade) They might be getting a 401 or 500 error.CauseIn this scenario, please make sure "Outlook Actionable" is available as an OAuth OIDC Provider in your instance. Sometimes this is dropped while upgrading the instance. How do you check it? - Navigate to 'System OAuth' > 'Application Registry' table: 'oauth_oidc_entity' - Search for the record "Outlook Actionable" If the record is missing, this is the issue.Resolution- Download "outlook_actionable.xml" file that is attached to this document. - Import it to the table as a new record. - After import, you can see that the Client ID field is "https://empravi.service-now.com" - Modify it to "https://<your_instance_name>.service-now.com" (change the "empravi" part in the Client ID to your instance name) - Leave the rest of the field values the same & save the record. Now, test this from the Outlook web app (it's better to use OWA for testing) This should fix the 401 or 500 errors. If the issue persists after uploading the xml, run a repair on the plugin which will update the client secret and OIDC Provider Configuration if it shows null.