The older Samsung TVs use a user developed Plex client. Unfortunately, the developer is not able to continue supporting it. The app has not been updated in quite some time.
On October 1, Plex dropped support for the TLS 1.0 protocol. As a result, many older Plex clients can no longer be used, as they cannot login to your Plex account. The Samsung client was not on the list (as it is not an official Plex supported client), but it may be affected as well.
You might be able to work around the situation, albeit with limitations. See this thread for details.
If the workarounds are ineffective, you’ll have to acquire a streaming box/stick such as an Amazon FireTV Stick, Apple TV, Nvidia Shield, Roku, etc.
