When trying to create a new query the initial window opens so you can select what to query on. When you click on the OK button to setup the query it crashes saying "Object not set to an instance of an object."
The system use has been disabled. While the user cannot be deleted from the GUI it is still possible to flag them as soft deleted in the database. The System user is used to run certain functions and cannot be deleted.
Run the following lines against the database to restore the system user.
UPDATE tps_user SET tps_deleted = 0 WHERE tps_title = 'system'
UPDATE tps_password SET tps_deleted=0 WHERE tps_guid = (SELECT tps_password_id FROM tps_user WHERE tps_title = 'system')