Completely out of the blue, and I'm not sure whether I'm in the right thread, but is there a way you can have a one-way exit tile link? So, you can enter it from (for example) Yoshi's Island and be transported to the overworld, but can't actually go back into Yoshi's Island from there. Does this require ASM editing to work or is it possible in Vanilla?
I'm trying to link world 1 to the main overworld. However, since I deleted everything in the original overworld, it says "invalid map FFF" in every option, when I click the yellow star button. How do I fix that?
Yes, you just go to File -> Layer 3 Submap -> Load Layer 3 of Submap, while in the Overworld Editor. Once you're done, click 'Save Layer 3 of Submap to ROM & ExGFX File' and load the ExGFX file in the OW Layer 3 Bypass.