Problem with walking trough object

Hello,
I have a problem with an objekt. Its like a tunnel but I cant walk trough it. I always run against the walls or there is something invisible and I cant go nearby. Is there any option for walking trough it or is it because its an objekt and I need to import it with other options? The building is a bit larger but this picture is an exemple. Nothing worked in a few hours. I hope somebody can help.

You need to open the static mesh and mess with the collision generation settings and see if you can get a better result: