I am able to load the participant box in pavlovia but right after that, a reference error appears. What can I do?
looks like you are presenting something is ocuring on line 89 of your experiment.
Click on the error message in your console corresponding to XPSUPRA1.js:89 - that should take you to line 89 and tell you where in your experiment you have an issue.
Best practice for fixing your issue is outlined here Syncing with a Builder experiment from Coder View
hope this helps,