release a bill to accounting with the problem of material ledger

Hi,

When i use vf02 to  release a bill to accounting , there is a system error:

Material ledger is not active in valuation area 2600

Message no. C+012

Under the same control area, another plant 4000 avtive the material ledger recently , i think it maybe the reason.

I don't want to active material ledger in plant 2600,

Who can tell me how to sovle this problem,

Thanks!