Data Model throws a nullpointer exception while trying to retrieve data

Summary:

I have created a data model with 2 data sets (one for employees and one for Contingent workers) - I have created an Excel Template that has 2 tabs for the data

The queries are exactly the same except for the Assignment Status Type = 'E' in one and 'C' in the other

I can run each query separately and get data but when I have both queries in the data set - it errors out

I was trying to run the queries in order to be able to get the data to export for my Excel Template but I get the nullpointer exception error.