If you have season titles enabled (under Manage library->Edit->Advanced->Use season titles), missing content doesn't get added in the correct location, the 'x/total' episode counts aren't displayed on existing seasons, and the seasons that do exist get reordered incorrectly:
If you have season titles enabled (under Manage library->Edit->Advanced->Use season titles), missing content doesn't get added in the correct location, the 'x/total' episode counts aren't displayed on existing seasons, and the seasons that do exist get reordered incorrectly:
With missing content disabled: