Installed latest version Plex for Windows on latest version Windows-10 Pro x64, fully updated. It fails to run, complaining about the absence of an Open GL 2.0 driver……
GPUz app claims Open Gl 2.1 capability is provided by the latest-available driver installed for the Radeon-X300 display adapter. And dxdiag app cites DirectX-12.
PATH includes the Plex executable folder, that does include the Plex-distributed ANGLE emulation files (as recommended in Plex startup failure message). Microsoft Store version of that ANGLE Open Gl emulator is also installed, and the system has been rebooted.