Microsoft Probes Outlook Copilot Button Glitch Microsoft is investigating a glitch that removes the Copilot button from Outlook after a recent software build, which the company attributes to a MAPI property that goes missing. The Outlook team said it is actively working to resolve the issue and restore user access to the feature. Microsoft has identified the culprit behind the missing Copilot button in Outlook: a pesky MAPI property that goes MIA after a recent software build, leaving users without access to this handy feature. The good news? The Outlook team is on the case, actively investigating and working to resolve the issue.