What does "You are not allowed into the destination" mean?
Occasionally when teleporting across Second Life, you may see the following message:
"Could not teleport. You are not allowed into the destination."
This basically means you don't have permission to enter a certain Estate (Private Island). It could be because it's not open to the general public and you're not on the allowed lists (found in World menu > Region/Estate > Estate tab), or you've been banned by that Estate's Owner or a Manager.
Under normal conditions, you should not see this message on the Mainland.