I had this problem like four days ago: I was adding a new tileset to use on my game, I got no problem in that part; the problem was when playtesting the game. Once I started playtesting the game, the character won't move on passage tiles. Is there any way I can fix that?
yes, by making the first tile in B (the one that always becomes a transparent one even if the tilesheet placed in B has a tile there) as star passability. That's one of the requirements to remember when making a new tileset, because B1 becomes the default passability for every position on a new map, so it needs to be star (which forces the program to look for A-tile passability in addition to placing the tile above the player)