Locks up or Crash on play

I started using 2018.3.5 and 2018.3.6 and I have had several crashes. This happens when I press the play button. I get a popup message (See screenshot) ![alt text][1]if I press cancel, Unity crashes. If I press save it locks everything up and I have to force quite. I have been seeing the same issue on 2 different computers with different files. I am running High Sierra on Both ( 10.13.6 ) Any Ideas how to fix this? [1]: /storage/temp/133543-screen-shot-2019-02-21-at-94606-pm.png