Bundle CSS Not Found 404 Error

I am having the same issue in version 4.1.  The Javascript bundles are generated correctly with minified with the .min.js extension.  The generated head  links point to the correct bundle with .min.js extension.

The generated CSS bundle file name, however, is incorrect. It does not have the .min.css extension, but the generated head link file name reference does.  This causes a 404 error.  I have the bundle and minify settings enabled for both.  What can be causing the link reference to generate correctly, but not the bundle filename?

ralphberger wrote:

I am experiencing this exact issue, and looking for answers is how I ended up here.

Is there any update on this issue?

https://github.com/nopSolutions/nopCommerce/issues/3440 is not very helpful either

I've had the same error but I found a solution!
I added the Bundler & Minifier (by Mads Kristensen) extension to Visual Studio.
Find the css in Solution Explorer that is not minified. (\Presentation\Nop.Web\wwwroot\bundles\)
Right click -> Bundler & Minifier -> Minify File.
If there is an error during minification process you will see the error and the line number in Error List window.