Make sure you follow the below steps very carefully:
1. Download program.
2. Run the program.
3. Examine the user interface.
4. Realize there is a button titled New.
5. Press the button titled New.
6. Realize a new dialog window has come into view.
7. Examine this dialog window, then think for a while.
8. Realize the new dialog is a form with settings (entry fields).
9. Fill out this form (the one which has recently come into view).
10. Realize there is a button titled OK.
11. Press the button titled OK.
12. If the program states a field to have not been filled out correctly, think for a while, then continue from step 7.
13. Realize there is a button titled Start.
14. Press the button titled Start.
15. If the status indicator located at the left side of the list item indicates Error starting, realize there is a button titled Edit, press the button titled Edit, and then continue from step 6 but fill the form out differently when you again arrive at step 9 (that is, if you make it there).
16. Try using application(s) and/or multiplayer game(s) for which you have set up port forwarding (contact the respective technical support team(s) if necessary (this does not include NetworkActiv)).
17. If it seems as though the newly set up port forwarding is not working correctly, think for a while, then realize there is a button titled Edit, press the button titled Edit, and continue from step 6 but fill the form out differently when you again arrive at step 9 (that is, if you make it there).
18. If things are still not working out and you believe you have set up the port forwarding correctly, think about your other network settings and arrangements, fix them if you see fit, then continue from the correct step.
19. If all seems to work well with the newly set up port forwarding, be thankful.
Congratulations! You have now set up port forwarding.
