When Solver Cannot Improve the Current Solution

The third stopping condition, which yields the message "Solver cannot improve the current solution," occurs only rarely. It means that the model is degenerate and the Solver is probably cycling. The issues involved are beyond the level of this User Guide, as well as most of the books recommended in the Introduction. One possibility worth checking is that some of your constraints are redundant, and should be removed. If this suggestion doesn't help and you cannot reformulate the problem, you will probably need specialized consulting assistance.