No, it's as much your mistake as anyone else's, if you have a professional or occupational license and you didn't get it renewed on time.  Your employer needs to know as well, but I very much doubt that your employer specifically told you or anyone else not to worry about your licenses, that they'd remind you when the renewal was due.  You should have gotten a notice directly from your licensing agency, and you might want to check to make sure that the contact information they have for you is up to date.