Use Automatic Scaling
Poorly scaled models are one of the most common causes of problems in which
the Solver appears to stop prematurely without reaching the true optimal
solution; it is a good idea to keep this box checked for all of your Solver models.
If your model is nonlinear and you do check the Use Automatic Scaling box, make sure that the initial values for the decision variables are "reasonable," i.e. of roughly the same magnitudes that you expect for those variables at
the optimal solution. The effectiveness of the Automatic Scaling option depends
on how well these starting values reflect the values encountered during the
solution process.