Hi Nandappa,
This means you are trying to add a key that already exists in that table. If you allow input of the key, make sure the key is the next possible value.
If you are generating the key, have a look at which value is generated (it's most likely repeated somewhere).
If you are using a UDO, there could be some corruption in the numbering table, you can use Help->Support desk->Restore->Restore numbering file and check if the problem is fixed.
Good luck.
Best regards,
Pedro Magueija
