Have you recently changed any passwords on your site? I would suspect that you have changed your mysql information on the server. You can edit the config-inc.php file in your photopost directory via ftp and make sure the mysql information in that file is the proper information to connect to the server. Or alternatively you can go to your sites control panel and change the password back to what it was. Either way should work there for you. If there is anything else we can help with let us know.