I get this error (screenshot below) and my WebGL build on itch.io does not load properly.
Game loads/works fine in the Editor and in the Windows builds.
I’m intermediate with Unity but in this area I’m not super versed.
I’m just not sure what to change, going off this error.
You should try to figure out where exactly this exception happens, what exactly is null and why it is null. Go back from the point of the exception and add plenty of logging to trace where the null value is coming from. Doing a development build will also give you better stack traces.
Just some speculation, the exception seems to be happening during Json parsing. Are you trying to load a Json file at runtime? The web is much more restricted in what kind of requests you can do and the load might be failing. Specifically, you have to respect the CORS rules of web browsers.