Solver: minimum value of two variables that result in x

Hello once again!

I have the following equation (changed the cells' IDs to letters):

=((1+(A/100))*((B*((C+1)/4)*(1+(D/50))+(D*10))+80))-E

B, C and E are fixed numbers.
A and D are variables.

I need the equation to be as close to 0 (zero) as possible.

However, I need the MINIMUM combination of A and D (basically, the smaller A AND D) that would make it 0, and not ANY combination.

How I've set up the solver so far:
Set Objective: the formula cell
To Value Of: 0
By Changing Variable Cells: A and D

Constraints:

A and D = integer
A and D >= 0
Formula Cell should be >=0

I can't solve, as it return the following error:

Error in model. Please verify that all cells and Constraints are valid.
Perhaps some cells that are not Variable Cells are marked as Integer, Binary or AllDifferent.

So I am asking myself... would the solver provide me the minimum combination of A and D that will make by formula = 0, or is it trying to give me anything that makes formula = 0 and, as many combinations would be possible, it is returning me an arror?

Any hint?

Thank you in advance!

EDIT 1: Solved the error by unmerging the variable cells. But the solver can't find a feasible solution.

EDIT 2: Changed from "To Value Of: 0" to Minimum and set another constraint of Formula >=0. It returns me a solution. But the question remains: is it the minimum value of A and D or just anything that solves my problem?