Same here. yesterday I was prompted from my Outlook for Mac to Update to Version 15.8.
I did this. After the update I was prompted to do an DB update, which I also did.
After that I restartet my MacBook and tried to open Outlook. After it opens it Crash und so I wasn't able to to anything in Outlook.
I now deletet the 15.8 version and my profile and reinstalled my 15.3 Version. I had to add all my account. Now it works, but it promptes me again to update to 15.8. But that I don't do again.
Is this a known Issue? Thanks for your information