GameScene.sks losing data?

I have a problem that occurs on some computers. I will add objects and set properties in GameScene.sks. When open another file and return to GameScene.sks the scene will be empty, all of the objects that were there are missing. Not just un-rendered, they don’t show up under the menu. Some times closing the project and reopening it will restore the file, other times not.

Has anyone had this problem? If so I’d really like to hear your thoughts, and any possible solutions.

I have two newer Macbook pro that has no problems. A slightly older macbook where this happens often enough that I need to find a solution.

I’m wondering if there is something in settings about how Xcode auto saves that might be causing problems.