How to save from 2016 Pro to 2015 Pro and then open in 2015

Hi guys and gyrls
I have problem with open drawings that ai maide in 2016 in 2015 pro
I have Sanderlight installed for 2015 and I whant to render some drawings that I made in 2016
I have saved the drawings in 2016 as 2015 but I cant open them in 2015
Is ther anyon out ther that can help me with this problem

So you used File>Save as… and changed the file type to 2015? How are you trying to open it in SketchUp 2015?

I go to open file and chuse the file thet I sawed from 2016 But get Cant open file

Are using File>Save as… to save the file in SU2016? And choosing to save it as a SketchUp 2015 file?

Are you doing this from SketchUp 2015?

Exactly what happens when you try? Do you get a message? What is that message?