Recommendations to try to solve this problem.
1. Create a new project and re-export your scene from Max as a Verge3D GLTF and save it to the new project folder and give that a test. If this results in it working it means that some modifications the html, CSS, JS files ocurred – more than likely.
2. Open Dev Tools in Chrome and provide a screen shot of the console log and the Network tab of the Dev Tools. Be sure you open the Dev tools to the window you are doing your puzzles on. Since the error is happening there…lets see the log.
3. Check to see if you Init Tab in the Puzzles Window and validate you do not have use compressed assets turned on. I don’t see any in your folder so … it it was on…this would cause a similar issue.
Post results…we might be able to figure it out.