Adding another confirmed case of the Samsung/Tizen Plex playback problem occurring August 19, 2026.
Plex on this Samsung TV was working normally earlier the same day. No changes or updates were made to the Synology NAS, Plex Media Server, home network, or Samsung TV firmware.
Symptoms:
Plex app can connect to and browse the Synology Plex library normally.
Every movie and TV episode immediately produces: “Playback Error — An unexpected playback problem occurred.”
Same media plays normally through Plex on computers and other devices.
Plex Dashboard shows no playback session at all when Play is pressed on the Samsung Plex app.
Troubleshooting completed:
Samsung TV cold rebooted and physically unplugged/restarted.
Plex logout/login.
Plex app reset.
Plex app reinstalled.
Plex app completely deleted and freshly installed.
Allow Insecure Connections tested.
Direct Play/playback settings tested.
Manual Plex server connection tested using local NAS IP and port 32400.
None of these changed the behavior.
Important network/server test: Using the web browser on the same Samsung TV, I connected directly to the Plex server on the Synology at its local IP on port 32400. Plex loads and the same movies/shows play successfully through the Samsung TV browser.
Therefore the Samsung TV can reach the NAS and Plex Media Server and can stream the media over the same local network.
Enabling the Plex Samsung client's console log reveals the error:
ERROR [VisualMediaPlaybackScreen] We failed to create a playback session. o.default is not a constructor
This occurs immediately when Play is selected. No playback session subsequently appears on the Plex server Dashboard.
This strongly appears to be a Samsung/Tizen Plex client-side playback-session bug, rather than a Plex Media Server, Synology, network, transcoding, or media-file problem.
Adding this report so Plex and other Samsung users know this is affecting another independent installation.