I’m sure this has more to do with my computer then anything else but I’d thought I’d throw it out there anywhere. (Have to keep my post count up )
I had a designer open. I wanted to look at a different project so I launched a second designer. (Something I do all the time). The login screen popped up. I started entering username/password when it cleared. (not detailing the debugging steps for briefness)
What was happening was it was trying to open many, many login boxes over top of each other. There were around 20 of them. It look like both Login and Cancel buttons were selected. If I clicked the login it would fail (because I couldn’t type admin/password fast enough). If I clicked the Cancel, everything would go away.
I cleared the problem by rebooting.