both diagnostics were performed, ticket numbers are 280492 (machine that initiated Unattended Access) and 280494 (machine that I was connecting to), timestamp is around 12:39

So as a result I can't even log into windows using remote assistant

I get this message every time I use unatended access and click on windows login page.
It doesn't have anything to do with UAC as no UAC popup can happen on the windows login page.
What can this be caused by?