Projects created in previous versions and X3

I am working on a project with a friend who is in another state. He creates a project and uploads to box.com. I download and open his project and do my thing with it.  I am using x3, and he is using version 6 I believe. I have noticed I am experiencing strange issues while working in the projects created in the older version. I have noticed my projects created in x3 are issue free. So obviously there is some version conflicts. Anyone have any tips or know if there is anything I can do to stabilize these or actually convert them to x3? I assumed just opening them in X3 would convert them, perhaps a bad assumption. For the most part, I am able work in it, just every now and then I can't unfreeze a track or take lanes and automation get lost.