I’m having a problem importing my SketchUp 2017 .skp files into Unity 5.4.2f2. According to this documentation all I should have to do is drag the .skp file into the Project tab of my Unity project and Unity should be able to import the model/assets on it’s own and this is indeed the case when attempting to import a .skp file that was created in a pre 2017 version of SketchUp. However, if I edit a SketchUp file in the 2017 version, save it and attempt to import that version of the .skp into Unity the import seems to fail without an error, the file that is imported seems to be an empty model or something. See the screen shot to see the difference.
The 2017 version is fairly new. It was just announced a couple of weeks ago. Most probably Unity doesn’t (yet) support 2017, as is the usual case with newly-updated software.
And this is a question for the Unity forums, as no one here could do anything about it anyway. (Unity Technologies and Trimble Navigation are separate companies.)
It only works with SketchUp 2015 files. For some reason they didn’t mention it in the manual (to this day).