Disallowed MIME type error on Windows

Apparently Windows system-wide MIME type configuration sometimes won’t load up JavaScript modules in certain browsers. The errors would be something like Loading module from “” was blocked because of a disallowed MIME type (“text/plain”) or Failed to load module script: The server responded with a non-JavaScript MIME type of "text/plain".

One suggested solution is to add the following to the bottom of the settings file:


    import mimetypes
    mimetypes.add_type("application/javascript", ".js", True)

See this Windows MIME type detection pitfalls article, this StackOverflow answer, or issue #201 for more details.