Trying to understand and fix Solver saying "all variables must have lower and upper bounds

I am trying to maximize the gross profit of a hypothetical VR headset but solver is continually telling me that "all variables must have lower and upper bounds." I am at a loss on how to alter the constraints, so any help is greatly appreciated.

As you are running Solver using the Evolutionary engine you must check under "Options" tab "Evolutionary". There is a tick mark in box "Require Bound on Variables" so you either uncheck that box or you do set max and min values on the variable cells. As far as I can see you have a max and min value on cell C5 (set in the constraint) but I can't see any max and min value on the cells in range D22:K22

Alf

Not sure why you choose to use the "Evolutionary" engine as the "GRG Nonlinear" engine finds the same answer as the "Evolutionary" engine but much faster and don't care about "Require Bound Variables"

Alf

Thank you for your input! How would I go about creating max and min values for D22:K22? Also, I am using an evolutionary engine because that is what is required of me.

How would I go about creating max and min values for D22:K22?

The same way as you set a min and max value for C5 i.e. C5>=C7 and C5<=C8 and you have also set a min a max value for K22>=2 and K22<=16 but you nee to specify the range. Is the range
D22:K22>=2 and D22:K22<=16??? I don't know but you should know the limitations for what min and max values this range can have.

Do you really need "Require Bound Variables"? Untick the box "Require Bound Variables" on the options "Evolutionary" tap and solver will hav no problem with finding a solution.

You could also change the "Maximum Time without improvement" from 120 seconds to 10 seconds. After some seconds you see the text in the lower left corner of the excel worksheet
"Incumbent 413 000 000" and this value stays the same telling you that solver has found a solution. You could perhaps reduce this time to 5 seconds but this depend a bit on how fast and powerful your pc is.

Alf