I always get error BC30198

[Katrin_Eva]

I am making a process in Data Table manipulation. And always get an error… What am I doing wrong?
How do I write this in the Column?

Step 19: In the Column Table 1, enter the column index as ‘0’ (column index of
Data Table ‘dt_users’), in the Column Table 2 enter the column index
as ‘0’ (column index of Data Table ‘dt_overdueBooks’) and select “=”
from the operation dropdown, then press OK.

[ppr (Peter Preuss)]

may we ask you for more details and some screenshots from the modeling?

[Katrin_Eva]

[ppr (Peter Preuss)]

Column Table 1: 0
Column Table 2:0

[Katrin_Eva]

[Katrin_Eva]

I did that but then the results were not what I expected when I save and run the workflow… So I am confused

[ppr (Peter Preuss)]

to illustrate it