DevTools failed to load SourceMap: Could not load content for http://localhost:3000/css/bootstrap.css.map: HTTP error: status code 404, net::ERR_HTTP_RESPONSE_CODE_FAILURE code example

Example 1: DevTools failed to load SourceMap: Could not load content for bootstrap.min.css.map

Delete /*# sourceMappingURL=bootstrap.min.css.map */ in css/bootstrap.min.css
and delete /*# sourceMappingURL=bootstrap.css.map */ in css/bootstrap.css

It is working for me.
I hope it will work for you also.
Namaste _/\_

Example 2: DevTools failed to load SourceMap: Could not load content for chrome-extension

DevTools failed to load SourceMap: Could not load content for 
chrome-extension://lhdoppojpmngadmnindnejefpokejbdd/browser-polyfill.js.map