Microsoft Outlook for Mac won't open

Thank you for posting here in Apple Support Communities, Macuseroutlookissue.

We understand that you're having an issue opening a specific app on your Mac computer, and we'd be happy to help. Is your Mac user account the only admin account on your Mac computer? If not, check to see if that app opens in another admin user account.

If you have the only admin user account on that Mac computer, we ask that you check for any available software updates for that app. If there are no updates available, we'd recommend that you uninstall and then reinstall it. Here's how: Install and uninstall apps from the internet or disc on Mac - Apple Support

If you're receiving a message saying that the app is from an unidentified developer, use the steps here: Open a Mac app from an unidentified developer - Apple Support

Let us know if that helps.

Cheers!

I followed this page and fixed issue.

https://support.microsoft.com/en-us/office/uninstall-office-for-mac-eefa1199-5b58-43af-8a3d-b73dc1a8cae3?ui=en-us&rs=en-us&ad=us

it seems like some old files make this problem, just remove them from ~/Library and reboot before re-install outlook 365 :)