Column Renamer & Default Value

Hello,

I’m looking at having a user identify specific columns which represent the Length, Width, & Height in a data set. I store the column names into multiple flow variables and then send the flow variables into a Column Renamer node.

When I connect a different data file to the Column Renamer, the Column Renamer uses the first column in the new data set which generates an error because it’s the same. Is there some kinda of error handling I should be implementing?