SAP Message RD156 - The selected data source is locked by another process

Diagnosis
Data should be read from a summarization level, but this level iscurrently blocked. This could be because it is being updated, forexample. Alternatively, data should be read from the CO-PA line items,but an update is being carried out.

System Response
The read request cannot be executed.

Procedure
Carry out the read request at a later point in time. The status of theDataSource is not changed.