There is a tileset bug that I have no clue what went wrong

[IsNikNoelaname]

I mark all the walls X but when I test play the game, the character still walks on the wall?
What should I do?

 

[Heirukichi]

Check your first tile in your B tileset, its passability MUST be a star.

 

[IsNikNoelaname]

Check your first tile in your B tileset, its passability MUST be a star.

Wow I changed that tile's passability to a star and it worked! But why does it have to be a star? Im pretty confused

 

[Andar]

But why does it have to be a star?

That is the zero tile, which means it is everywhere where you did not place a different upper tile

maps are stored by numbers, and the default number for every tile is zero.
That means that every tile in your map is filled with that first B tile when it is created.

For this reason the tile has to be transparent (the engine guarantees that, even if your B sheet has a tile in that position it will vanish in the editor) and its passability has to be star, because star means "look at the ground tile below to check for passability".

if it were passable, it would make all your walls passable and if it were impassable it would make all your floors impassable as well as the upper layer has priority over the lower level on map passability.