Template instance to pop up window pass parameters

Put TCNumber in a label, too. Is the template repeater's .indexParamName exactly matching TCNumber ?

Wait.... Where does your template get HeaterNumber if you are using the template repeater to supply TCNumber? Sounds like you need to use dataset mode in your repeater, in order to supply more than just an index number to the template.

If you are already using dataset mode in the repeater, make sure your dataset column names exactly match the template parameter names.

The template gets the number from the container (the pop up) which is handed HeaterNumber. And the checkbox uses it in the indirect tag path. It's constant across the repeated templates. Only TCNumber increments.

I wasn't using dataset mode originally. I tried dataset mode though, and I couldn't pass in HeaterNumber's property path to the column HeaterNumber.