Sometimes on Dreamscape there are areas outside of the custom zones where the map isn't coded. It can happen simply from walking from one location to another, and or clicking objects. Players who host giveaways also host them in these normal RS places such as, "Taverly, Draynor Village, Seers Village", and other discrete areas. This is quite common to happen in some cases. So for this solution you will need a staff member to teleport you home. Those members are Moderator(s)+ 

You can request for one on an alternative account. 

How do I know if im stuck?

If you were to login the screen would be black and similar to either or.