OKB9 Profit center wise assignment is not allowing.

Dear Experts,

Here iam facing problem like, In OKB9 setting valuation area wise allowing for cost center assignment, Profit Center wise not allowing for cost center assignment.It means it will allow to assign cost centers, but while transacting error troughing like co object missing, if we make setting like valuation area, it not throughing any error.

We can think why cant we go for assignment with valuation area.But we have number of profit centers under one plant, Plant is equal to valuation area, Here iam suppose to go by profit center wise only, please give me a better solution to come out of this issue at the earliest.

Thanking u in advance

Chinni