mp4box made mp4 unplayable

[bkey]

A script is using MP4Box -inter 500 file.mp4 to make files fast start. Some of the files had very long file names with characters, which apparently mp4box has trouble with. Well with these files 2 files were created ending in _ts.txt and _RTP.XML and now the .mp4 files are unplayable. I've searched around and see that this is a known issue with mp4box. Is there any way to make the .mp4 files playable again. The file size seems to be the same as originally, but the show 0:00 on video players and won't play.

Any help is much appreciated. User doesn't have backups readily available.
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[hello_hello]

I rarely work with MP4s but you could try opening them using MKVMergeGUI and resaving them as MKVs. If that works and you need MP4 you should be able to then remux the MKVs as MP4s again. I don't know much about MP4Box but Yamb is a GUI for it which will open MKVs.
Or you could simply try opening the problem MP4s with YAMB and remuxing them.

[Baldrick]

Have you tried latest mp4box builds ? From gpac, http://gpac.wp.mines-telecom.fr/downloads/gpac-nightly-builds/