Event 'all present' breaks due to slice
Internal Server Error: /events/admin/181/all_present/
AssertionError at /events/admin/181/all_present/
Cannot update a query once a slice has been taken.
Internal Server Error: /events/admin/181/all_present/
AssertionError at /events/admin/181/all_present/
Cannot update a query once a slice has been taken.