File works with 2.5.x but not 2.6.x versions of Avidemux (Sample Included)

[mean]

It's not mp4
It's some sort of mpeg PS/PES file
Not very standart

[mean]

It is h264 inside mpeg PS, which is very uncommon
Quick workaround : Change from mpeg PS to mpeg TS wich ffmpeg
ffmpeg -i ~/Downloads/ch05_20151103143356.mp4   -acodec copy -vcodec copy ch5.ts

It is very fast, no reencoding involved. The output file can be opened fine.

[douche]

Your workaround worked perfect, Thanks mean!