https://support.proctoru.com/hc/en-us/articles/360036574592-MacOS-X-Catalina-And-Big-Sur-Users-Important-Notice

I got on with ProctorU after all was said and done and made sure I could connect. Also, downloaded Firefox just in case (w/ the proctorU extension). I'm pretty sure you could also use proctorU chat box before your scheduled time and make sure all is okay! That's what I plan on doing again just for peace of mind!

Had some extreme difficulties with Big Sur. I had to reschedule because I was on the line with proctoru for over an hour; I ultimately got it to work after multiple tries; I had a virus software I had to delete. I ultimately had to reschedule but trying to keep my eyes on the prize.

Same thing happened to me -- I did the same thing (deleting apps and trying again). Mine worked after I restarted my computer then went into preferences and deleted a few old/larger files. Hope this helps!