4.17 Seems to crash... a lot

Does the particle Emitter Menu window crash when trying to save it or edit the values? with me the engine was lagging terrible until I
had to drop the all polys down on my landscape, then it came right, and i have no more lag and all that hard drive activity I used to have
when trying to move the camera around in the editor… So I stopped putting in big mountain terrains into my maps.