Cannot log into Messages on mac mini late 2014 with Monterey 12.6.8

Sorry for delay and thank you very much. This has been a nagging issue for years and I really need the tool for sharing between piphone11 and mini. That said, I will be away from my mini much of the next 24 ghostly and goulish hours. Will definitely continue checking this thread for any and all suggestions over time. I'll add one more point before copy paste. Since I upgraded from capitan to monterey the mini performs much slower. And also since that time (couple months) blue tooth on mini no longer works. Perhaps all connected problem?

End of report

Now I don't remember how i got there. Thought I opened system prefs and pasted /Library/LaunchDaemons/com.apple.installer.cleanupinstaller.plist into the search. But now that does nothing, I am just lost. I don't see a way in sys prefs - users to do anything to a library. So sorry, I have no idea how to open the hood on this thing, much less what's under it....)

Okay installed FAF, found file, deleted, rebooted. First thing I tried upon reboot was messages. Same problem of can't sign in "unknown error". Then closed that out and went to bluetooth. My keyboard has long been paired and functioning correctly. I can now pair with my phone and or an external speaker but no sound plays through the speaker once paired.

Ready to try anything but I'll be away from the big screen mini until sometime Monday.

Thank you x 100 for perseverance!

Also when I look in messages/ preferences/ general I can see it is not set up with my name and such. However i cannot click in/fill in anything.

Trying this again, thank you.

Okay when I get to library then launch daemons there are two folders:

remote pair and fpsd .plist

I need to delete one of those?

Thank you

Going to try to leave file of DriveDx report here for your perusal. Also Smart Utility says Passed. Thanks