When duplicating an existing Purchase Blanket Agreement, error message appears 'This entry already exists in the following tables (OAT1) (ODBC -2035) [Message 131-183]'

Hello Everyone,

In SAP B1 9 PL 4 and 9.1 PL 4 , after duplicating an existing Purchase Blanket Agreement and saving it, I get a message :

'This entry already exists in the following tables (OAT1) (ODBC -2035)  [Message 131-183]'.

Is this a bug?

Thanks - William