Invisible walls to prevent walking into the bunker walls

[playme3000]

I just started mapping yesterday. Everything went pretty smooth thanks to following daddy dirk dirk and RingoD123's tutorial. I'm pretty much finished but when testing i've notice i can walk straight through the bunker walls (those grass inclines for the sides). I've noticed an "invisible" tileset and assumed that would be invisible walls but turns out they aren't. Anything i'm doing wrong or any ideas on how to prevent people from just walking into the wall?

Edited August 26, 2022 by playme3000

[Hermago]

idea 1: you can modify tile properties? something like, TileBlockStyle then select solid.

[stuck1a]

Yeah simply use an invisible tile (like the one in the sheet invisible_01) and add the property TileBlockStyle = solid or solidTransparent