SAP Message BMA_GEN006 - Worklist update (table BMA_WLST) canceled

Diagnosis
An error occurred while updating the worklist (function moduleBMA_WLST_UPDATE).
The editing mode was &V1&.
Here the letters I, D and U have the following meanings:
I: Worklist items must be added.
D: Worklist items must be deleted.
U: Worklist items must be edited.

System Response
No data was saved.

Procedure
Inform your system administrator if needed.