DevTools failed to load SourceMap: Could not load content for chrome-extension://pgjjikdiikihdfpoppgaidccahalehjh/webspeed.js.map: HTTP error: status code 404, net::ERR_UNKNOWN_URL_SCHEME code example

Example 1: devtools failed to load sourcemap when debugging react native

Open Developer Tools, 
go to "Settings" for Developer Tools, 
then uncheck Enable JavaScript Sourcemaps under the "Sources" settings.
Restart Browser if needed

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

Open Developer Tools, 
go to "Settings" for Developer Tools, 
then uncheck Enable JavaScript Sourcemaps under the "Sources" settings.
Restart Browser if needed

Example 3: 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

Example 4: DevTools failed to load SourceMap: Could not load content for http://127.0.0.1:8000/bootstrap-select.min.js.map:

You need to go into Dev Tools settings and you need to unckeck 
"Enable JavaScript source maps"
"Enable CSS source maps"