Server Version#: N/A
Player Version#: Version 1.81.0.4012-a9d3f098
Windows 10 Enterprise 22H2 x64
I use Windows as a user without admin rights, and I have a separate account for admin operations. When the Plex for Windows updater process runs on app startup it prompts for UAC elevation but after providing my admin account credentials it always fails with:

Downloading the installer from the Plex website, running it as my regular user, and then providing admin credentials when prompted by UAC fails in the same way.
Running the installer As Administrator and providing my admin credentials when prompted by UAC succeeds.