Hi There,
If this is a project that you made since Jan 4th then that will be the problem, as pavlovia is currently running on a snapshot back up.
If you are testing your experiment, copy all files to a new folder (delete and .git files, they could be hidden so make sure to view hidden files) and push a new project for now.
More details here: Getting studies running again on Pavlovia
Hope this helps,
Becca