In HandiTax, these errors can occur in an individual tax return when item M2 Label E = Y and item M2 Label A has the number of days entered.
Check the information completed in the Individual tax return in the items below:
Item M2 Label E.
Item M2 Label A, is it a leap year?
In the Clients Tax Form Details window, ensure the Year Start and Year End dates align with the tax year.