Failure to Load CTAT errors

[eharpste]

I ran into an issue that seemed to be browser dependent but was easily fixed. Basically, I had the wrong path to an HTML file in my training json so the flask serer couldn't find it. When running under Firefox this manifested as a CORS request did not succeed error. On Chrome it manifested as a basic 404 error. In both cases the console just kept printing the Waiting for CTAT to load. Attempt: NNN error message. Maybe we could improve the text of that message to say something like "are you sure your html path is correct?" Or maybe we could start putting together a wiki page of common debugging tips or something.

[eharpste]

This maybe solved by restructuring AL_HTML, we should confirm pre-summer school.