Comment by dreamcompiler

They do this to Office 2021 routinely if your computer is offline more than about 30 days at a time. I run LittleSnitch to keep Microsoft blocked; my copy of Excel periodically goes into "read-only" mode. So I unblock Microsoft, let Excel talk to the license server, and then block Microsoft again.

Now Microsoft says my Excel will never work again. I'm pissed. Time for an FTC complaint.