Plex не поддерживает воспроизведение образов дисков:
No current Plex apps support the playback of ISO, IMG, VIDEO_TS, BDMV, or other such “disk image” format content.We do not encourage users to use such formats.
Но если по каким-то причинам нужно, то можно добавить их в библиотеку:
The default media scanners in your Plex Media Server will intentionally skip over unsupported disk image format media.
If you for some reason do wish to include these unsupported formats in your library, you can do so by use of a custom scanner.You’ll find an unsupported versions of such a scanner for “Movie” and “TV” Library sections attached at the end of this article.Remember, you will not actually be able to play the disk image content!
https://support.plex.tv/articles/201674 ... mat-media/