An "Operation is invalid for a Memo, General or Picture field" error suddenly started to occur for an existing biz object that was created to retrieve data from a table that contains one memo field. The error occurs on the DbDataAdapter.Fill command in our DataAccess biz object.

The select statement that executes contains a union clause and had been working fine until a couple of days ago. The biz object has not been changed, either. When tracing the code, all parameters that are sent to the biz object are valid. The select statement that is built based on the parameters is valid.

Any idea as to what might be causing this error?

Thanks in advance...
Patty