I'm trying to do some editing of tags on MP4 video files. Some work great, some give me the dreaded "file "blahblah.mp4" can not be opened for writing" error.
These files do not show me any tag information in MP3Tag (I am using 2.49)
However, if I drop the file into iTunes, I can see the tag and edit it without a problem.
I am using Mp3tag 2.49 via Wine on OSX Lion. My friend who first showed me the problem is using same version on Windows XP.
I am not sure what else to provide, so let me know.