When upgrading to the new firewall GUI, some comments are put into the new configuration files, but as they may contain invalid characters (>, <, etc.), the rules cannot be edited any more. I recommend accepting some of the characters. If characters are not allowed, they must be removed from the comment.
should work now: http://git.ipfire.org/?p=ipfire-2.x.git;a=commit;h=65c9b3a50815587bc212160465c92b6150e6fb77 http://git.ipfire.org/?p=ipfire-2.x.git;a=commit;h=abb3cfcc9ef1ffec5235ead3b9cad4014c141aa9 (already merged)