Diagnosis
A further exchange was labeled as active in table BON_MAPC_INF_DNL.

System Response
The system stopped the current exchnage to avoid data inconsistencies.

Procedure
If an exchange has been started, this is defined in tableBON_MAPC_INF_DNL. At the end of the exchange process, the relevantentry is deleted again.
Check whether an exchange is still running.
If this is not the case, it may be that an earlier exchange was notcompleted correctly. In this case, check table BON_MAPC_INF_DNL anddelete the relevant entries. Before you delete, check that there are noblocks from previous exchanges that have not yet been processed.