Error during release to Accounting

While releasing Contract I am getting the error as :FI/CO interface:

Balance in transaction currency.

Process:I have a contract wherein there is one Manual Condition type(For Ex:ZSQD)

which is Statistical and also I enter condition record during punching of the contract.After generation of Contract we make

the billing and accounting document is generated.But for one plant I am facing the error as "FI/CO interface: Balance in

transaction currency".This error only for the value of ZSQD?

How do I solve this error?