DevTools failed to load SourceMap: Could not load content for chrome-extension: code example

Example 1: 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 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