Thanks for posting this solution kierad, this error was driving me insane!
I can confirm that you don’t need to sync your experiment with Pavlovia, it is just necessary to clear your browser cache.
(Although if you want the latest version of your experiment you should export HTML manually or ensure that HTML is set to export on save in the settings).
I am having this issue and the listed fix isn’t helping. I have tried this with two experiments to see if I can tease apart the issue, let’s call them Experiment A and Experiment B.
I was able to use the local debugger with Experiment A once, but then the local debugger wouldn’t update with my changes. I then tried to load Experiment B in the local debugger, which tried to run Experiment A’s PsychoPy file in Experiment B’s folder.
I have restarted my computer, deleted the browser cache, and resynced both experiments to Pavlovia. Any advice?