We just had 2 customers calling because one of our programs is crashing when trying to play .mp4 files. They both updated windows yesterday night.
After investigating, this is the filter responsible:
Microsoft DTV-DVD Video Decoder
C:\Windows\SysWOW64\msmpeg2vdec.dll
{212690FB-83E5-4526-8FD7-74478B7939CD}
Using GraphStudioNext and trying to render any .mp4 file with logging enabled shows that this filter is the last one directshow tries to automatically load before crashing.
Even trying to manually add that filter to an empty graph makes the program crash.
Renaming that file to something else avoids the crash.
The file is protected by TrustedInstaller, so you will have to take ownership of that and then give yourself permissions to rename it