Objects aren't acting solid

Quick as I have to run.
my walls and other objects are not acting like walls instead my character ( an empty and camera) are passing through them and sometimes collid with some invisible object. all normals are facing the right way. I know there is a simple explination for this, but I have no idea what I missed.

instead my character ( an empty and camera) are passing through
Right there is your problem. Never use empties to detect your collisions. Use an invisible mesh instead.

Is your empty dynamic?

Make a box around your hero, make sure he just barely fits inside, make it invisible and set bounds to box.

Thank you. I will try these out. I knew it was something small and stupid that I missed.