Why cant I touch my model. Please Help!

When I try to go anywhere near my model I cant there always seems to be a massive invisible block around it. I used rhino to create the model then used Blender to convert to .obj and then into UE4. It may be a problem with Rhino, it may be a problem with Blender, it may also be a problem with UE4 and the way imported it.

I have uploaded the model in a .zip file for the purpose of my help, so please do not reupload or reuse

Ok I’ve narrowed it down to collisions, when I add a collision no matter what size it wont let me go near it but when I don’t have one I can walk straight through

Follow this ! Setting Up Collisions With Static Meshes | Unreal Engine Documentation

I think the collision is now a big box
you have to delete this and generate a new one.