TableRow To Variable Loops With GroupBy

I am trying to perform a GroupBy function using two constant variables, and a third set of variables groups in succession via the TableRow to Loop Start method. However, I get the following error:

Execute failed: Input table's structure differs from reference (first iteration) table: Column 2 [name=Tagged:X,type=StringCell] vs. [name=Tagged:Y,type=StringCell]

...where Tagged:X and Tagged:Y are the first two values of the flow variables.

What am I doing wrong?



Which node makes the error?  It sounds like you have a node configuration which is relying on a setting that is not yet controlled by a variable.  Also, whenever I hear loop and group by, I am obligated to mention the group loop start node which we recently added.  You may find it nicer to work with...