Today I thought I would convert that AVI to an MP4 and presto, it plays on the Blu-ray. I don't know why that would make a difference, perhaps you do and if so, please tell me.
You haven’t disclosed the make and model of this set top player. These extra features (file playback) are not standardized at all, and will be different from one model to the next. Only the manual can tell you what will work and what won’t work. Only authored Blu-ray Video disc and authored DVD-Video disc playback are mandatory for these players; other features are optional for whatever the manufacturers thought would help sales at the time of introduction of that model.
