Outlook Add-in command button disabled when composing
问题 My add-in has a MessageComposeCommandSurface ExtensionPoint that adds a button to the ribbon when the user is composing a message. I expected the button to always be enabled when it is visible (e.g. when the user is composing a new message or replying to an existing one), but sometimes it is greyed out/disabled and I'm not sure why. Does anyone know the exact circumstances for when an add-in ribbon button is greyed out/disabled? 回答1: Try to disable some COM add-in and then enable it again. In