Running movie on Pavlovia works in Firefox but not Safari and Chrome

URL of experiment: pilot_eventseg_German_12m [PsychoPy]

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Description of the problem:
I have an experiment in which participants are shown two movies (one 2-minute practice and one 12-minute main) after which they answer memory questions. My experiment works fine on Firefox and returns the data I need. However, when I try to run it in Safari, the experiment loads, shows the practice video, and then returns an error after the first frame of the main video is shown:

When I try to run the experiment in Chrome, the experiment never loads and returns the error:

All my videos are in a resource folder. Does anyone know what the cause for these errors might be and how I can fix them? Thanks for any help on this in advance!