DevTools failed to load SourceMap: Could not load content for http://localhost:8080/resources/sap/m/library-preload.js.map: Connection error: net::ERR_CONNECTION_REFUSED 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