Diagnosis
You want to transfer revenues. This is not possible at present.
The reason is that revenue updating was changed in Release 2.1B. Thedocuments posted before this release must be corrected using the XPRAreport RKRKU2CH before installing Release 2.1B. This report has not yetbeen started or has not ended successfully. Further revenue transferswould lead to faulty transaction data.

Procedure
Inform your system administrator.
Read the release information CO_ISTBUCHUNG_2. Then start the reportabove.