That can happen if you are a view or security administrator and the view group you selected for the view is not one that is enabled for your user profile group. Enable the group for your user profile so that it shows in the left panel. Otherwise, just select a different view group for the view and be sure it is one that already displays in the left panel.
Note: This scenario doesn’t impact you if you have a casual or advanced level of access because the only view groups that you can save views to will be those already enabled for your user profile.