I get this error during the install process.

Catchable fatal error: Argument 1 passed to Concrete5_Model_GroupPermissionAccessEntity::getOrCreate() must be an instance of Group, null given, called in /content/sites/c/b/cbuk.org.uk/web/concrete/core/models/page.php on line 322 and defined in /content/sites/c/b/cbuk.org.uk/web/concrete/core/models/permission/access/entity/types/group.php on line 39

Any ideas?

Mike