Uuum well could be several stuff, you could be behind a router or firewall, only thing hou have to do then is host on a certain port and make sure your router passed trough ip packets of that incomming port to your pc on that port, or make sure your firewall doesnt block that port. (Can configurate the router though its IP with a password, hard to find how but i'm sure its on internet and maybe you allready , or the person that knows more about your home network, know how to do this.)

There is also something like a world.hub var, need to set it i think, only i had this problem like a year ago and i never hosted or uploaded anything ever since.

Good luck, maybe other peple have some suggestions too.

Greetz Fint

Oki you say so, ask someone else, dont know enough about this, but i think you sould try OR open a port (on wich you host) OR turn the whole firewall off and try it. Though you didnt give me any inforamtion about if this is the first time you ever hosted or not, if it aint then maybe thinking of what changed between your last host and now will solve the problem.