“There was a problem playing this item. The video did not start playing in time”

I’m sorry to inform you but the time has come to do one of two things. I was recently faced with a choice of keeping my old WebOS LG and knowing end of Life with Plex was approaching fast, so I did not repair my TV and bought a new Shiny LG OLED. To say I’m happy with my choice is an understatement, Plex LG app is now version 4.15 and has regular updates. Alternatively a Shield or Apple TV were considered prior to a unexpected Radio card failure which renders the remote useless.

  1. New TV
  2. Buy a box like Roku, AppleTV, Nvidia Shield

Plex are dropping support for WebOS 1 and 1.4

Support pages:

Plex for Smart TVs & TiVo - #106 by markus101

https://support.plex.tv/articles/204080173-which-smart-tv-models-are-supported/?_ga=2.214895511.1228126706.1575159261-622477649.1575159261