4. The Set Target Cell values do not converge.

This message appears when the Solver is able to increase (if you are trying to Maximize) or decrease (for Minimize) without limit the value calculated by the objective or Target Cell, while still satisfying the constraints. Remember that, if you've selected Minimize, the Target Cell may take on negative values without limit unless this is prevented by constraints on the Target Calls or other cells.

If the objective is a linear function of the decision variables, it can always be increased or decreased without limit (picture it as a straight line), so the Solver will seek the extreme value which still satisfies the constraints. If the objective is a nonlinear function of the variables, it may have a "natural" maximum or minimum (for example, +A1*A1 has a minimum at zero), or no such limit (for example, @LOG(A1) increases without limit).

If you receive this message, you may have forgotten a constraint, or failed to anticipate values for the variables that allow the objective to increase or decrease without limit. The final values for the adjustable cells, the constraint left hand sides and the objective should provide a strong clue about what happened.