Hello There,
Thanks for writing in! Those errors are just missing sourcemaps. They are requested by developer tools when possible, but won’t interfere with anything.
Basically it’s a way to map a combined/minified file back to an unbuilt state. When you build for production, along with minifying and combining your JavaScript files, you generate a source map which holds information about your original files. When you query a certain line and column number in your generated JavaScript you can do a lookup in the source map which returns the original location.
Please check out these links:
Hope this helps.