While trying to create new Digest on one of RSS feeds I got a message as above. The address is perfect so what the problem? Website is in Polish language but I don't think this matter.
Website: http://www.samar.pl
RSS feed: feed://www.samar.pl/__/__la/pl/__ac/sec,118/__Ostatnie-wiadomo%C5%9Bci-motoryzacyjne-kana%C5%82-RSS-serwisu-SAMAR.html
Any help?