Admin Module frontpage has gone - How do I get it back?
Try using phpMyAdmin. Backup again, then show the system table. Change the status of the problem module from 1 to  0 from phpMyAdmin. Then refresh Drupal pages to see if it resolves it. Other modules might be the issue so try process of eleimaination, toggling 1 to 0. If the 0 works, try and uninstall then reinstall if practical.