Hello, and thanks in advance.
I imported a large .fbx level into UE4 but the collision does not match the wireframe. Basically, my player is running above the map. Is there an easy way to contour the collision to the wireframe?
**Disclaimer.: I am very new to UE4, so I apologise for if this question is noobish. I tried several searches. **
These documentation pages would be a good place to start if you’re new. 
Generated collision doesn’t work by tightly bounding to the mesh. It generated convex hulls that give an approximation. You don’t always want the collision to match exactly to the mesh, this can give bad results with character movement or other physics objects colliding along with the added performance cost of additional collision hulls or faces.
You can set the mesh to use Per-Poly collision, so that it uses the faces of the mesh as its own collision, but I don’t recommend this as a rule of thumb to apply to everything. Generally there are instances where it would be really useful, but its something that you need to weigh the options and decide. This can be enabled in the Static Mesh Editor > Collision Complexity > Use Complex Collision as Simple