CORS and MIME issue on localhost

I’m having an issue with CORS and MIME type on local host. I don’t see this issue on our production web site.

Developing on my work machine using localhost I am seeing this when loading a page with an a notebook embedded with javascript.


Loading module from “” was blocked because of a disallowed MIME type (“application/json”).

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at (Reason: CORS request did not succeed). Status code: (null).

I don’t understand why I’m getting the disallowed mime-type either?



Once again I have shot myself in the foot. Seems I was using a removed version of the notebook.

Re imported and all is well…