Error on Scheduled Refresh: Table contains blank values

I have a dashboard scheduled to refresh daily, but each time I get an error that says:

"Column in Table contains blank values and this is not allowed for columns on the one side of many-to-one relatioship for coulmns that are used as the primary key of a table."

I went to this table and edited the query to Remove Blank Rows, but I still get the error every time I try to refresh the data.