Hi! I've reviewed your picture, and this means that the area you're trying to access is still loading in the background so you can adventure there. You can see in the top left hand corner of the screenshot that there is a Spiral icon still loading behind the message. Once that icon disappears, the area you're trying to access should be ready for adventuring.
Sometimes you'll see this message when you've been playing the account on multiple computers or recently re-installed the program.