unity crashes when importing small assets

Hi, I am using Unity 5.2.2f1 I am trying to import a large file from SketchUP 2014 and the progress bar gets near the end and just seems to freeze for hours, while it says importing small assets. I just have to close Unity down. My model is very large and it probably has too many faces etc, but if there is something I can change in Unity to get it to work, then I would be very grateful.

I get the same problem at least once each two weeks.
To fix it, each time I delete the Library folder and reimport the entire project.