The given key was not present in the dictionary

I created an SSIS package with several Execute SQL Task to Data Flow Tasks. In each Dataflow task I have an OLE DB Source connected to a SQL Server PDW Destination. Only one of the data flows keeps giving me the error: "The given key was not present in the dictionary." In the data flows I am loading data from one server to another. This particular one, earlier, had a space in a column name on both sides and had to be fixed or it wouldn't map correctly. (I'm not sure if fixing that error changed anything.) So I'm not sure how to fix this error that I get. Any suggestions would help.

Thanks

Are you referring to missing attribute key? Try adding ISNULL or CASE statements to your columns where NULLs are present.