I’ve been struggling with this issue since 4.19.2.
I’m using a Razer Blade 14: Intel i7-7700HQ 2.80GHz, 256 SSD, 16GB RAM, Nvidia GeForce GTX 1060
After reading multiple posts and finding no real answer to the problem, I’ve just tried using the “Verify” option for 4.20 in the Unreal Laucher. I’m 20 minutes in and have been opening and closing the material editor on and off (which used to crash my UE4, guaranteed).
For the Epic Games Staff and anyone experiencing the same issue, try using this method and let us know if it helps you too.
Best wishes, Mara