Note: This is specific to Android / Android TV clients. Your log files list only Plex Web using Chrome.
If you cannot update the version of Plex Media Server:
- Disable Plex Media Server secure connections (Settings → Network → Secure Connections = Disabled)
- Disable Android / Android TV client secure connections (Settings → Advanced → Allow Insecure Connections = Never)
If necessary:
- Restart server
- After server restarts, restart client
Note: For Plex Web, you will need to access your server using the local IP address, http://pms_ip_address:32400/web. Also, Plex Relay will no longer be available.
See Connection Error when playing films on android tv app - #3 by FordGuy61 for additional information.