Could you send me the file you are trying to import?
Send me your email address and I will. Also, I dont think its a file issue at all. I believe that it is a browser permissions issue. Look at the response I posted on the dev page.
I missed that message of yours. "The devicemotion events are blocked..." shouldn't be a problem, it's just a warning and it doesn't prevent the rest of the code from working.
I've uploaded a small update, which at least helps with Tazshelby2016's file. In that case it was invalid geometry in JSON.
So it still doesn't work for you? I'm out of ideas, your file is loaded normally for me. Maybe you should try another browser, maybe something is wrong with your browser's settings/permissions (as you said). But in this case there should be messages in the console, not just that "devicemotion" one.