Changing Selected Characteristics in Planning

Hi Guys,

I have just removed a characteristic value from the plan selections cos I want to use a relationship to derive it instead. But the system is not allowing users to access the planning area after the change.

When I change it back to its original state it works but if remove the charc. it will not work.

Is there anything I need to do after I change planning selections to enable users access planning.??

Urgent