Same issue, and with multiple experiments. If you’re using soundfiles, Pavlovia does not yet work with that unfortunately. If you’re using custom Python codes, can you post them in this thread? We can take a look at it.
One thing I did which solved one of my problems was delete one of my codes which directed the participant to a survey. Pavlovia didn’t like that.
See also my thread here and have a look at kdoelling’s answer.