DevTools failed to load SourceMap: Could not load content for http://localhost:3000/static/js/main.chunk.js.map: Load canceled due to load timeout code example

Example: 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"