Diagnosis
No product cost collector with the naming rule "not specified" has beenmaintained for the material entered. Postprocessing records existed forthis material before the system was converted from a release< 45a to a release > 45a.
The first time this material is backflushed, a one-off internalconversion of the postprocessing records takes place. Postprocessingrecords are no longer written per run schedule header, but per productcost collector. In each run schedule header for this product costcollector, a one-off internal conversion must take place. For this,blocks are set on the corresponding production versions.

System Response
A production version, for which a conversion must take place, hasalready been blocked.

Procedure
Try to execute the backflush once more. Ensure that none of theversions for this material are blocked.