Help me debug code snippet?

Bug Reports
1

I customized this in the Client Letter several years ago, but now the paragraph is showing up for clients who don’t need to make instalment payments. Did something change recently? Perhaps field codes? Anyone able to help with the logic?

{{# Instalments }} {{# InstalmentPaymentSummary.M[4] + SingleAnnualPayment.M[0] > 0 }}
Federal tax instalment payments
Since you owe taxes of more than $3,000 for {{ Constants.CurrentTaxationYear}}, you will be required to make instalment payments to CRA during {{ Constants.CurrentTaxationYear + 1 }}, according to the schedule on the next page.
{{/ SingleAnnualPayment.M[1] > 0 }}
{{/ InstalmentPaymentSummary.M[4] > 0 }} {{/ InstalmentPaymentSummary.M[4] + SingleAnnualPayment.M[0] > 0 }} {{/ Instalments }}

2

This has not changed and is what we have in the default client letter so should work:
{{# Instalments }} {{# InstalmentPaymentSummary.M[4] + SingleAnnualPayment.M[0] > 0 }}

That paragraph is also wrapped with this condition in our default:
{{# SingleAnnualPayment.M[0] > 0 }} {{/ SingleAnnualPayment.M[0] > 0 }}