I’m now running an experiment online. It is a large experiment including presentation of videos and images. I tried to compress the videos and images to my best ability and use format of videos that should not be problematic as suggested by others Media formats suitable for online studies — PsychoPy v2021.2
The experiment ran just fine for most participants (it usually takes ~5min to load the whole experiment). However, for about 5 out 30 participants, it got stuck at some point or some of the videos failed to be loaded. This happened regardless of the internet speed and the browser they used. Sometimes the problems got fixed when they load it again on a different day, sometimes not.
Could anyone give me some hints on how I should troubleshoot this problem? I normally asked these participants their internet speed, how long it took them to load the experiment, the browser and computer system they used. Thanks a lot!