I still have it on my Windows 10 computers (Lifetime License). No problems on the Mac or Windows. After reading the security Big Sur has I my drop the third party security when / if I upgrade to Big Sur. I'm still debating on that.
I did this Security update in December on Catalina (2020-001) https://www.wilderssecurity.com/threads/apple-security-updates.368333/page-9#post-2974288 During the update I got this: I had to do First Aid to complete the update. After the update was completed the Mac worked fine until the next Security update on 1 February (2021-001). https://www.wilderssecurity.com/threads/apple-security-updates.368333/page-9#post-2986958 During this update the black screen with the circle showed up twice for about a minute. But this time it continued the update without using First Aid. I never had any problems with update or upgrades on the Mac. It may be possible that Apple mixed a Big Sur file in the updating of Catalina, I don't know for sure. Hopefully when I upgrade to Big Sur it will fix this problem.
That's a tad disconcerting. Although this is another reason I'm not a huge fan of third party security programs as they can often be the cause of these sort of problems.
I always uninstall all third party security software before updating / upgrading. So during these updates Malwarebytes was not on the computer or any traces of it.
Your Suggestion has Been Granted: https://www.wilderssecurity.com/forums/all-things-mac.145/ We began the forum with a few threads there, mainly starting about 8 months ago. If you find any other important thread that should be there, please list them here, and we'll move them as time permits. Thank you all for your input!