This could be one of two things:

1.) This is common glitch that users experience from time to time. It is usually fixed by either going to a different location in the World, or waiting for it to go away (WeeWorld may be performing maintenance causing it to happen). You may also trying clearing your cache, in the event your browser is using an older version of the World that is bugged.

2.) Your account may be compromised, and whoever is using your account may be using it in that World location. If there is a risk of your account having been stolen, you may wish to change your password as soon as possible. (If this occurs at every World location, this is probably not the issue.)