Error(s):
Fully transparent tiles were found.
You make the screen with the first tileset, then switch to the transparent one.
What does that mean?
Download both tilesets. Put them in your tileset folder as two different tilesets (e.g. tileset0.png, tileset1.png) Make a screen with the tileset # you chose for this one:
Then scroll through the tilesets until you arrive at the one that is transparent (
)