I am using Sketchup Make 2015. While trying to upload a SKP model that was made in another version, I get the following message: "This file is version 8.0.3117. You will not be able to load this file in a previous version of SketchUp if you save it in SketchUp 2015.
What is the resolution?
Either don’t save it after using it in SU2015 or use File>Save as… and change the version to SketchUp 8. This assumes you or someone will need to open it in SU8 in the future. Otherwise there’s nothing you need to do.