Resource blocked due to MIME type mismatch (X-Content-Type-Options: nosniff)

Question

I am developing a web page using JavaScript and HTML, everything was working good when I have received this list of errors from my HTML page:

The resource from “https://raw.githubusercontent.com/dataarts/dat.gui/master/build/dat.gui.min.js”   was blocked due to MIME type mismatch (X-Content-Type-Options: nosniff). The resource from “https://raw.githubusercontent.com/mrdoob/three.js/dev/build/three.js” was   blocked due to MIME type mismatch (X-Content-Type-Options: nosniff). The resource from “https://raw.githubusercontent.com/mrdoob/three.js/master/examples/js/renderers/CanvasRenderer.js”   was blocked due to MIME type mismatch (X-Content-Type-Options: nosniff). The resource from “https://raw.githubusercontent.com/mrdoob/three.js/master/examples/js/renderers/Projector.js”   was blocked due to MIME type mismatch (X-Content-Type-Options: nosniff). The resource from “https://raw.githubusercontent.com/mrdoob/three.js/dev/build/three.js” was   blocked due to MIME type mismatch (X-Content-Type-Options: nosniff). 

These errors appeared after an automatic browser update (Mozilla Firefox), may be something has been changed in the set up. Do you know any way to solve this problem?

Answer 1

Check if the file path is correct and the file exists - in my case that was the issue - as I fixed it, the error disappeared

Answer 2

This can be fixed by changing your URL to use a mirror/proxy. Instead of using GitHub:

https://raw.githubusercontent.com/svnpenn/bm/master/yt-dl/yt-dl.js Content-Type: text/plain; charset=utf-8 

Use a third-party cache:

https://cdn.rawgit.com/svnpenn/bm/master/yt-dl/yt-dl.js content-type: application/javascript;charset=utf-8 

rawgit.com was a caching proxy service for GitHub that has shut down since 2018. See its FAQ