1. Go to an enrolled course in the iOs Moodle App.
2. Go to topic with the file (PDF/MP4/PPT etc)
3. Tap the file name, then "Open the file"
4. A grey screen opens, but instead of showing the file, it displays an alphanumerical filename with no extension, along with filesize. ie "09676eea63d1b58112f702ab996513fc 3.5 MB"

The file can be shared using iOS sharing but it only sends the file with the alphanumeric name and no file extension. It is possible to append the file extension to the file and it opens correctly.

Different display settings ie "Embed/Open/Force Download" produce same error.
The file uploaded to Moodle has no spaces or non-alpha characters in the name, and has the correct file extension.

iOS v9.2.1
Moodle App v2.8
Moodle 3.0.2+ (Build: 20160121)