Problem with mesh collision

Hello! Sorry if this is a very simple question but, I’m kinda new to UE4… Anyway, I was wondering if there was a way to make it so you can collide with meshes with the way their geometry is built, example: I’m trying to make a wall with window frames so I can put windows there but, I cant go through the frames. I also have this problem with a curved mesh, I seem to just stand in the air… If this is a simple fix please let me know how to fix it, if your confused just tell me to give a better explanation. Thanks!

to prevent your character from going through the holes, you can use blocking volumes (they are some sort of invisible walls) and for you curved asset, open your static mesh, and find the collision complexity parameter, and turn it to complex