Ok i thought i should post this in here since noone realy looks in the bugs forum , anyways i figure out how to fix the multiplayer bug where it shows the single player menu .
Ok first , insert your FPSC disck in your hard drive , wait a few seconds so it can transfer to the computer click start , my computer it should say FPSCDISK or somthing like that , right click on it then click OPEN you will see a bunch of files , click setup and wait for it to install again after the installation is done run fpsc and , build a test multiplayer and see if it works
-Thank you .