If that still doesn’t work, I can try to send these files to you directly, let me know if you want to try that.
Scrap that! I have managed to open it on my iMac which is plenty. Don’t need help, Thanks 
Hi Tyson, I am brand new to Sketch Up and am using the exercise files right now. Well, I was - until I got to Core concepts and am now finding that - like DFD design, I am unable to open any files apart from the first Quick Intro exercise file. I would really appreciate it if you would send me the rest of the files in that zip file. Many thanks.
Lucy
PS I’m on Mac OS Ventura 13.4.1 MacBook Pro, and iMac OS Ventura 13.4.1(c). I have the SketchUp Pro educational licence (purchased in April).