Black lines in model

I have imported a model in 3DS format to blender. The model shows annoing black lines all around that weren’t visible before (see attachment). We use the model in our own software so rendering options don’t help. Is there some kind of tool for removing the black lines?

Attachments


two things come immediately to mind.
The first is to check normals… in EDIT mode, select the whole object and choose mesh >> normals >> recalculate outside (CTRL-N)
The second is that autosmooth button right there in your screenshot. Select the mesh and give it a push. You may need to manually assign hard & soft edges.