This is being reported in the WP forums, and sure enough I ran my CSS though the validator and an error popped up which was not there before. So when and why did the jigsaw.w3.org/css-validator change ?
CSS Validation changes ?
I'd tell you but I don't trust you.
I think it was updated a couple weeks ago. Probably when the XML validator was upgradted/updated
I just checked my own CSS and I don’t have any errors, but there is a list as long as my whole body of warnings. 🙁
Very strange…I have the same as Cyndy, no errors but a huge list of warnings.