I'm using version 12.4 (though the bug was also in 12.3).
I'm having a folder with a perfectly working video file in mp4 format. When I view the folder in details view everything is fine, but I get the following error when I switch to thumb view:
DO keeps working, so before restarting I can switch back to details view. When I stay in thumb view and restart the program, I get the error again, restart, etc.
I tried stripping the first two minutes of the video, and then a thumbnail is shown, but the error remains. To save bandwidth I uploaded the first minute of the video here: stevenvh.net/files/vpo2015.zip. This file also causes the error.
I noticed the error after the last Windows update. I can't remember, but it's possible that before this update the error didn't occur. At least I never encountered it, and the video has been there for a while already.
PS: I thought there was just a problem with that one video, but it appears it occurs for all .m4v/.mp4 videos