Hi,
I exported the 'Template:Mainpage/styles.css' from Wikipedia. But when I try to include the css via <templatestyles src="Template:Mainpage/styles.css" /> it shows me not the formated text I'd expected, at least nothing formatted. If I corrupt the line (e.g. src="Template:Mainpage/styles") I get an error.
Direct including via <templatestyles>…</templatestyles> is not possible anymore, so I'm not sure how to find the failure. Did I forget something?
Mainpage/styles.css is classifed as sanitized css.