Can't Create New Message

Question

I am having issues with Outlook for Mac new version. All of a sudden, I 'Can't Create New Message' pops up when I go to Reply to an email, send a new email, etc.

Now one of the most bizarre parts is that if I quickly reply to an email and send it, the message pops up, but it states it is sending it. Then it shows up in DRAFT, however, the individual on the other end receives it.

If I do not reply before the pop up happens, nothing goes out, but if I do, it appears to send.

So frustrating. Have reset, deleted account so many times.