I am currently experiencing an issue when doing something as simple as using a query to select a single recipient and then trying to udpate its email with a update activity. For some reason, the workflow is returning the following error "cannot modify column of non-key preserved table" and the SQL:
02/19/2019 1:13:34 AM writer WDB-200002 SQL statement 'UPDATE (SELECT iRecProcState Ign FROM wkf621559747_605_1 out, NmsRecipient tgt WHERE iRecProcState >= 0 AND out.iPKey_1=tgt.iRecipientId AND ((COALESCE(tgt.sEmail,N'###NL###')=COALESCE(out.sFld742326736,N'###NL###')
02/19/2019 1:13:34 AM writer ))) Upd SET Upd.Ign = -1' could not be executed (error in position 240: 'Upd.Ign').
Last week I didn't get this error at all... it appeared this week.
Please check whether the recipient email is a primary key or not. You can't update this activity if the email is primary key in Recipient schema and check the operation in update activity is only insert or both (insert/update).
And make sure that the data type is same for both source and destination.