I am trying to manipulate a file created by my partner in sketchup pro 2017 on his computer with my computer in sketchup pro 2018. I can manipulate the smaller files he creates but the one large file he made I cannot manipulate without it freezing. If i try to save anything it freezes and i have to force quit. PLEASE HELP! thanks
Commonly the bottle neck is the graphics card. This seems to be especially true with Intel graphics. Although we see it more commonly with Windows operating systems, it occasionally shows up on Mac, too. You might ask your partner to first purge unused stuff from the file and then change the style to Monochrome so that your graphics card doesn’t have to process textures and materials to display the model.
Unless your partner’s computer is the same model and same configuration as yours, it is entirely possible for a model he builds to be ok on his but to overload your computer, especially if you have less RAM or (as @DaveR suggested) a different graphics card. This is a question of each computer’s capacity, not of SketchUp 2017 vs 2018.
Turn off all the layers and shadows. If that doesn’t work maybe try: select all, copy, and paste into a new drawing file.