Error in saving the incoming or outgoing shipment changes in warehouse.

There are configurations under Warehouse for managing the incoming and outgoing shipments which provide different steps for receiving and delivering the prodcuts, whenever I am trying to modify those configuration, system throws the following error "IndexError: list index out of range".

This is specifically happening while I am trying to change the "outgoing shipment" configuration. My current configuration is 3-steps (pick + pack + ship) and I am trying to change to (Ship only), and it throws an error in doing this.

Does any one know what could be the problem? Am I missing any configuration?