ATV 4 "Couldn't create the playback session for this item"

Hello,

I recently made the switch from a QNAP Nas to external HDD on my Imac. Now I’m receiving an error on a whole bunch of media when I try to play them: “Couldn’t create the playback session for this item”

I’ve tried refreshing the item in plex, tried deleting the whole library, and starting from scratch. Nothing works. However, if I try to view the same media on the Roku, it works. WTF?!

Anyone have an idea what might be happening?

I should clarify that I am running a brand new installation of Plex media server on my Imac. Media is stored on an external drive.

Is it perhaps Direct Playing on the Roku and when you try it in the Web client it transcodes? Check free space on the disk.

Ok, so on the ATV4, it gave the error message mentioned above. I tried to play the same file on my Imac, in Firefox, and get this message:

“Streaming this media is unsupported”

Tonnes of disk space available.

I’ve discovered that if I manually remove the offending Tv episodes (or whole series folder) from the library directory, and then return it to that library folder, plex picks it up again and is able to play it.

I have no idea why, and that clearly isn’t a solution, but at least it allows me to keep watching things.