Overriding stylesheet templates of a skin doesn't work

Let's say I have a default skin.

And I'd like to override the less/general.css template and also to change text color of the non-existing pages from normal color to red. So I add a new overriding template: less/general.css: and add the style color:red !important for the .wikicreatelink class:

Then I save the document and open the Home page where I have a link to a non-existing page. The text to non-existing page is not red and my new styles are not in the list of styles for the respective elements:

Overriding the footer.vm with an empty template works as expected: the footer just disappears, but when I override any of the stylesheet files, it doesn't work at all.

I'm using xwiki-platform-distribution-jetty-hsqldb-14.9 distribution on Windows 10.

Originally posted this problem on the forum.