The VideoLAN Forums

I have several mp4 files that I want to view at 1.25 or 1.5 speed. However with VLC player, going to the playback tab, I can't select playback speed (seems almost like it's grayed out but it's not grayed out).

I'm able to play other files with my VLC player at different speeds but not these school mp4 files.

Also tried quicktime player which only lets me jump to 2x speed but doing so plays the video at 2x speed but no audio.

is something wrong with the files?

Yes. VLC cannot change the pace for all media, just most, so the representation in the menu is accurate. This is an issue with the files which cannot be fixed in VLC.