I tried multiplayer with "FPSC-Game.exe" version 1.4, in "languagebank\english\textfiles\fpsc-050.txt" at line 619 is "www.game-guru.com" link. Here is the result:
The IP address box showed my IP. When select "HOST GAME" the level is loaded and i played, but if you select "JOIN GAME" sometime crashed, sometime saw this (the uploaded screenshot) ,no friends IP! Any of this "fake" host players can be joined, but when loading over, "waiting to join..".
Change line 619 with "www.fpscreator.com" and here is the result:
Once again the IP is there, "HOST GAME" working, "JOIN GAME" showed "No Games Listed" (when your friend is already host or otherwise).
Change line 619 with "www.thegamecreators.com" and here is the result:
My IP is there, "HOST GAME" crashed the game most of the time, "JOIN GAME" always crashed.
Change line 619 with "www.google.com" (i know, it's funny), result:
The IP is there, "HOST GAME" working fine, "JOIN GAME" showed 5 empty hosts, none of them can be joined. I don't even try this one with my friend.
Delete line 619, result:
The IP is there, "HOST GAME" working, "JOIN GAME" showed "No Games Listed".
The conclusion:
FPSC V1.4 always showed your IP. No working servers at this moment!