When First run the web in debug mode,the css dosn't work

The Error Message in chrome browser is:
GET https://localhost:51859/css/Homepage.Head.styles.css?v=MRXNhU_B93Up9SAOmLkgm-QX3D4 net::ERR_ABORTED 500

I'm a  beginner,Somebody can help me to resolve the problem,thanks a lot!

At the same time, the request url:
https://localhost:51859/js/Homepage.Footer.scripts.js?v=E1tT7OPHZGQE1JOdY6qnn3kx8zY
run well.
In the code path:
nopCommerce\src\Presentation\Nop.Web\wwwroot\bundles

I can see a JavaScript file named:
'js'Homepage.Footer.scripts.js__E1tT7OPHZGQE1JOdY6qnn3kx8zY.cache

But in all of the solution, i can't find a css file named:
Homepage.Head.styles.css

SO how can I genrate or get the css file?

The problem is probably due to the using of NUglify V2.12.0.
The error message in Nop.web.exe console  shows:
NopCssMinifier.cs:line 37
The code is

var result = Uglify.Css(input, new CssSettings());

it's going wrong  when use Uglify  to minify and compress the  file  
nopCommerce\src\Presentation\Nop.Web\Themes\DefaultClean\Content\css\styles.css
But here's the strange thing, I create a project to test the styles.css by use Uglify,it works well.
Finally, I Comment the code:

var result = Uglify.Css(input, new CssSettings());

The web program runs well.

Check your setting in App Settings
See https://yourwebsite.com/Admin/Setting/AppSettings
> Bundling & minimization > Cache directory
Cache directory is a valid location

You can check with disable CSS Bundling & minimizing from Setting > General setting > Minification panel

You can uncheck, clear cache, and restart the app
verify you can get the result

and if you get then you can troubleshoot into that

Yidna wrote:

it works,thanks a lot!
what trouble me  is  when first login the web in admin,the css makes no effort,so the page looks
very  disorderly and original,it's difficult for beginner to find the appsetting.
I think i should read the document for developer  one more time.

Thanks to Yidna!