Dear Sir,
It is not the problem in formula, yet it is in the fact that money that is needed to be invested exceeds the money that will be gained from project. You can check whether you entered all the data correctly, and if it happens that you did, this project is nonprofitable.
There is no need to pay me for this advice, but please answer me whether you found a solution for this problem.
Best regards,
Djordje Gajic