So here is the result: Suddenly UE4 doesn’t like the hyperthreading ! As I switched of the hyperthreading, UE4 runs on my PC. Has anyone an idea why UE4 crashes with 4 HTs (hyperthreads) suddenly? Until septembre UE4 runs with HT and as from octobre UE4 (and the hole win 10 too) crashes with HT. I don’t know why this behaviour… ON my laptop UE4 runs with 6 cores and 6 HTs…