Different than a similar post’s OP’s issue here. Has multiple reports unrelated to the OP’s issue.
Tracking - Exactly the same issue.
Have managed temporary work around by using Plex Media Player for Mac, but not my preferred permanent solution for all installs. and has been a PITA to even get that working.
Any ideas would be appreciated.
Have deleted and reinstalled Plex for MacOS multiple times but just crashes immediately.
Under-edumacated guess: It looks like a breaking change in macOS that affects Plex’s Qt library or one of Plex’s callbacks for Qt related to OpenGL. If this were the case, either Plex’s Qt fork or Plex would have to be updated.
I’m having the same issue as well, immediately after the latest Catalina security update.
It looks like Plex player for Mac Quits unexpectedly and Plex Desktop App Crashes are reporting the same problem.
Someone in dev please help!
This is a problem for multiple Apps. Google Earth Pro, RStudio, Stellarium all failed when I updated. I noticed Qt in all the tracebacks.
Jumping in to report that I’ve got the same issue, macOS 10.15.7
OK, I think I might have identified where the problem is and a workaround (that seems to work for me at least)…
In my case, the bug happens when I have a dock with an attached monitor plugged in when I attempt to start Plex.
To workaround the problem, unplug the dock (you must unplug the dock) and directly connect a second monitor to the Mac (via HDMI or TB). Start Plex, it should come up on the second monitor. You can then drag Plex onto your first monitor. Reposition the window on the first monitor a couple of times (to make sure that the saved window position is definitely on the first monitor), then quit. Restart Plex and should come up on the first monitor - so you can now unplug the second monitor if you want.
NOTE: This is a workaround and not a fix because as soon as you go back to using your dock (with no directly connected monitors), the problem will come back. You can plug in the dock while Plex is running and everything keep working, but as soon as you quit and attempt to restart, the problem will come back. You can have one monitor via a dock and one monitor directly connected, that works, but if you’re using a dock in the first place then that may be of limited use to you…
Same problem here.
I can’t use Plex at this time 
Plex, please fix it!
Same thing is happening to me.
Server: 1.24.5.5173
Client: 1.35.1
MacOS: Catalina 10.15.7 (Mac mini late 2012)
crash_log.txt (145.3 KB)
Plex.log (55.8 KB)
Plex.1.log (55.8 KB)
Same here. Please fix it!
Hello,
same Problem here too under a Mac Mini (Late 2012) with the latest Catalina Security Update.
I hope you can fixed this Problem fast …
Regards
I have the same issue. Mac Mini Late 2012 with Catalina 10.15.7 with latest security updates installed. Please fix this, since the only alternative is to keep using Plex Media Player which is a lot outdated nowadays…
Kind regards
Does someone of the Plex Team feel responsible to fix this issue?!
Well, I just installed the new 1.37.0.2706 app, hoping this would fix the issue, and…
Nope. Same problem. Come on, Plex! PLEASE FIX!!
I just did the update as well, with no change. Plex continues to crash immediately after it is launched.
Same issue here too. It has been an issue for a couple of weeks. I tried uninstalling and reinstalling but no joy! Please fix
New Plex Version from November 10, 2021:
Same Problem. Nothing fixed.
Hey Plex, whats up?!
I found a solution for the issue and posted it here
Thanks a lot, I found a fix in that thread as well!
For anyone complaining against Plex support, well, it is not their fault: the problem comes from Apple’s last security update patch (2021-007 as of today) and Plex is not the only application impacted.
Good news: the next security update seems to fix it (2021-008, currently available in the beta developer program) → no more issue with Plex for me (Macbook Pro 2012)
Final version of security update from Apple is out, it fixes the issue.
