surver

Niko is correct. It is servers fault and it's a common problem. You were (probably) in a different virtual world. But one thing makes me wonder is this the right answer and that is that other people could see you but you didn't see them and that isn't the case in the virtualworld problem. If you happened to be in a different virtualworld you wouldn't see anyone and no-one could see you. And the chat problem is weird too...