OK, I'm attempting to make a tileset with invisible tiles. Two of them are a square and a circle. However, they don't show up on the masks screen and you can't collide with them.
Is this a common bug, or something weird? I can upload the tileset if it helps...

Just don't put the tiles in the tileset, and put them as solid objects in the mask. Don't use black or that purple color in the mask on the tiles, or they won't be solid.

I checked the other masks and they were 0,11,7 so they worked. I changed the two to that and they appeared fine... yey thx =)