I know, it sucks! this thing happend to me I installed my vc:mp just yesterday. and I got the same error you just have to wait untill they release a good version like me.
I installed vice city multi player and it starts but when the loading is allmost finished an error appears and says something like VC:MP has crashed, an exception occured, exception at adress:........ I hope you guys will be able to help me...