I have a plane im using for a wall, my character will walk through one side but not the other, ive selected two-side in face options but it doesn work. does anyone have a solution, apart from duplicating the plane (becasuse this will cause slow down when i duplicate my walls) and making it into a cube doesnt help. Ive also fiddled with face normals outside but no luck. Thanks for any help
i’m not sure i understand you fully but…
YOur character is dynamic yes? your using Force - apose to dloc ?
Your character is not travelling to fast that collisions aren’t being detected?
Occasionally a blender bug can mean things go through faces. This is due to rounding up/down of co-ordinates.
To resolve that bug keep everything inside, or close to the initial 3D grid.
hope this helped, if not, post a link to the file
-Luke
are you sure that collision is selected in the face options?
im dloc so thats probably it, is their a way around it? because the collision is detected on one side of the face.
For true collisions you really need to use either LinV or Force. You may be able to get it to work if you scale up your world, but it’s a gamble. Dloc just isnt reliable for collisions (although force doesn’t work that well sometimes either 
)