Mail Merge Fields Not Working with Calc But Do Work With Base

I’m running Libre Office 5.0 on Ubuntu (12.04 and 14.04). I’m new to using Mail Merge. I have a single field whose data source is a sequential list of integers. When my data source is a column in a database table, printing with Mail Merge gives the desired result. Each page printed has the next number in the sequence. However, if I do exactly (as far as I can tell) the same thing but using Calc as the data source, what is printed is <field_name> on every page.

I would like to resolve this because for our simple needs, using Calc is easier. (Base isn’t installed on all computers.)

I resolved this. It was simply user error, but unfortunately, I cannot say exactly what I was doing wrong. Anyway, it is working. Therefore, I think I should close this question.