Videos not in sync with audio

I am using code to create a python experiment using psychopy. In this code, I am showing videos to subjects while they perform a task. At some point (didn’t happen when I started building my code) my code started presenting the videos and the audio out of sync. Both the visual and audio aspects come from the same Mp4 files.

Please Help!

It’s generally a performance issue. It can be caused by memory load if you’re loading a lot of videos as MovieStim at once, or if you changed which audio plugin you use, or in some cases even if you change the display size so the movie is not playing at its native resolution. What have you changed from when it was working?