Yeah i have the same problem
But i think i have a solver for it
As you maybe have seen almost all tilesets have a couple of empty spaces in them that arent used fo a wall/tree/canister or something So you go to the database make 1 of them from an
O to an X and you make a new event next to it and give it the graphic you just made an X
and nothing else thats it.
That's how i fixed it
EDIT: GODDAMNIT I WOULD AHVE BEATEN YOU IF MY INTERNET NOT WENT OUT CRAPPY INTERNET