Diagnosis
You want to edit a batch of material &V1&. None of the batchesof this materials are classified. The material &V1& or a batchof this material is currently being processed in another session. Toprevent a batch from being assigned to a different class from thematerial or to prevent two batches of the material from being assignedto different classes, batches of material &V1& cannot be editedif the material or one of the batches of the material is being edited.

Procedure
Finish editing material &V1& or a batch of this material in oneof the parallel sessions.