my problem is I cant walk trough an object or on this objekt. Is there any option I need to click or import the model with other options. I cant walk trough the object or nearby because there is something invisible. I guess the mistake is that its a complete model or something like this.
what probably occured is that you had auto generate collision set to enabled when you imported the mesh and it created a large rectangular collision volume. to verify this open your mesh in ue4 and enabled the showing of the simple collision by clicking collision near the top then selecting simple. this will show you the shape of your collision. now to fix the issue you will need to create your own custom collision in a 3d modeling software, or disable collision on the mesh and add in some collision volumes of your own in the level such as a few box collisions.