Subtitles Undefined

[TheDreadPirate]

You need to change the file name to include the language code. Documented at the link below.

https://jellyfin.org/docs/general/server...le-example

So for yours it would be "The.5th.Wave.2016.en.srt". You can also add dispositions like "forced" or "default" to the file name so that they are enabled by default, for example. Those flags are also documented in the above link.

After you've changed the file name you will need to rescan for the update to be picked up.