Hi all!

Why is my solver working only one time and then crashing? What I mean is that I have to shut down my Excel before it will solve again.

For example:
A1 = 2
B1 = 2
C1 = A1 + B1

Then solve that so, that C1 = 8 by changing cell B1. Of course the answer is 6 and the solver will find that answer. OK. Then I keep the solver's answer. Then I change the value in cell B1 back to a 2 again and try to solve it again. (this is a stupid example but at least you get the point). Now the solver says: Error in model. Please verify that all cells and constraints are valid. I don't quite understand this. Why is it not solving it for the second time?

If I save that document. Close it. Open it again and then try to solve it, the same message will apper. IF I copy/paste those cells into worksheet 2, then I can solve it again for 1 time

Really interesting problem. I found this on the internet:
Error in model. Please verify that all cells and constraints are valid. (13)

This message means that the internal "model" (information about the adjustable cells, target cell, constraints, Solver options, etc.) which is created by the Solver.xla add-in and passed to Solver32.dll is not in a valid form. You might receive this message if you are using the wrong version of either Solver.xla or Solver32.dll, or if you have accidentally modified the values of certain hidden defined names used by the Solver, either interactively or in a VBA program. To guard against this possibility, you should avoid using any defined names beginning with "solver" in your own application.


I have installed the whole office again --> .xla .dll files sould be OK. That leaves number two --> I have accidentally done something that messes everything up (OR some program I have has done that)

Any suggestions?