This "server certificate does NOT include an ID which matches the server name" sounds like you have a CERT issue (that your server name is not listed in the CERT).This "Cannot
declare class Error, because the name is already in use in
C:\\xampp\\htdocs\\support\\include\\class.error.php on line 43" sounds like something is being loaded and then the same thing is being loaded or again or a class is being re-declared. Did you download osTicket from http://osticket.com/download?Have you altered the source?Did you clone your existing installation?