Computer freezing completely while playing

@HowEmbarraSim  When I saw the MemTest error, I went right to that, because it's an obvious error.  However, now that I'm looking at things more closely, I notice that you're supposed to have 32 GB total (4x8 GB, right?), yet your last two dxdiags 16 GB installed rather than the 32 that showed up in your older ones.  Have you run the dxdiags with half the RAM removed?  If not, it would be quite strange for your system to suddenly start not recognizing half the memory.

If you played this most recent time with all 32 GB installed, please remove two of the modules, leaving two that match, and try playing with just that 16 GB installed.  It's still more than enough to support Sims 4 and some multitasking, so performance should be fine.  If you get a crash, pull those two modules and try the other two.  Since the only MemTest error occurred with all 32 GB installed, it's worth trying, that is, if you didn't try it already with this most recent crash.  By the way, did the game itself crash alone, or did your computer freeze too?  A Sims 4 crash after 90 minutes of play might be a system error, or it might be Sims 4 being its usual difficult self.