Try this
I've got this same error when I try to open a .mov file by QuickTime 7.
I convert this .mov file from a mkv file via FFMPEG.
Here is my way to solve this problem:
Step-1, Open Mkvtoolnix.
Step-2, Add the original .mkv file in the list of "Input files".
Step-3, In my case, I found 2 objects in this .mkv file aside of VIDEO and AUDIO, they are subtitle and chapter XML. Uncheck these 2 objects.
Step-4, Click "Start muxing" button to create a new .mkv file, which only contains VIDEO and AUDIO.
Step-5, Convert this new .mkv file to mp4/mov/m4v again.
I am not sure this solution will fix everyone's situation, but it solve my problem. Good luck!