ES6 modules in local files - The server responded with a non-JavaScript MIME type

Question

I get this error:

Failed to load module script: The server responded with a non-JavaScript MIME type of "". Strict MIME type checking is enforced for module scripts per HTML spec.

The project is run from local files, eg.: file:///D:/path/project.html.

Works without problems in Firefox, but doesn't work in Google Chrome. I want to test it this way for development purposes - it's more comfortable than creating a server and remembering what port is it on.

Answer 1

A simple fix for me that wasn't listed here was this:

I had an import statement bringing an object from a different file, which I did via this line:

import { Cell } from './modules/Cell';

What broke the code and caused the MIME type error was not having .js appended to the end of ./modules/Cell.

The updated line fixed my problem:

import { Cell } from './modules/Cell.js';