Microsoft says Copilot buttons still missing in classic Outlook

Microsoft is still investigating an issue where Copilot and Copilot Chat buttons disappear for some classic Outlook on Windows users. The bug affects Copilot Chat (Basic) and paid M365 Copilot (Premium) licenses and appears after updating to build 20026.20182 or later.

• Copilot button disappears above the ribbon and in the Outlook sidebar
• Issue occurs after updating to build 20026.20182 or later
• Cause: Outlook cannot find MAPI property PR_PROFILE_USER_SMTP_EMAIL_ADDRESS_W
• Workaround: enable the "Show Apps in Outlook" option in settings