Keep getting "There was an unexpected error during playback. Please visit our forums if you continue to experience problems." in Plex web ONLY. Plex apps are ok

Still trying to fix this, 4 months on (thanks Plex for continuing to ignore this, along with not supplying Linux with a Media Player…), and seems that it’s a known issue, that they started to discuss, and then forgot about: Plex Server not picking up system wide fonts on Linux