Exchange 2013 on-premise, AADConnect sync to O365. Since I'm using the on-premise server for just basic, local things - scanners, etc., we never renewed the commercial cert when it expired 2 years ago. Used a self-signed cert and everything worked fine.
So it expired 9/1 and I created a new one in the EAC. It all seemed to work fine, no errors. IE complained about it but after installing it to the Trusted whatever IE was happy.
But I have no connection from O365. I discovered a remote Powershell cmdlet, Test-MigrationServerAvailability and it most certainly says it can't connect to the local EWS due to an invalid cert.
I just don't understand what I did last year that worked and this year it's not.
My boss will never buy a commercial cert for this thing, and I really don't want to decommission it and have to set up O365 for our scanners...