@BluebellFlora Ill try that out and tell you if it works.
But I would like to tell you that I previously got it to work once on my own the old fashioned way. I just shut off my computer multiple times and the base game eventually worked. Also my friend who has mbp 2015 can get the sims 3 to work by just shutting off her computer about 5 time, I don't know if this info helps at all but its sort of like my last last resort.
Also when I edit the files should I changed intelHD6000 back to ivybridge?
Edit: It didn't work on my macbook air ):
