The steps for Actual Cost in a new implement case

Hi,

I would like to know the steps for impelement ML/AC in a new case.

for example, Our system is a new case and we posted the materials in 2010/07 by using movement type 561.

the first period is 2010/08, therefore only 2010/08 has material transactions.

when we do post closing in the CKMLCP costing run, the system show C+715 error message.

What is the corrective steps for activate material ledger and actual cost for a new case?

Thank you very much

BR

Hung