DevTools failed to load SourceMap: Could not load content for https://rawgit.com/Microsoft/TypeScript/master/lib/typescriptServices.js.map: HTTP error: status code 404, net::ERR_HTTP_RESPONSE_CODE_FAILURE code example
Example: 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