Same issue here. Using the ID, or URL fails – even though the same string works with another 360 viewer.
If you edit the PHP file here around line 45 to the following
if(strpos($file_headers[0], ‘Not Found’) !== FALSE)
It should fix it. Basically, right now it makes the assumption an empty header means the url doesn’t exist – which isn’t true. So instead, restrict it to only show the error when it gets a 404.