It doesn’t matter, it’s any landscape. In my case for example I created “Basic” template project > Landscape tool > (basic terrain settings, 63x63) hit create > Now I have landscape and I edit that terrain, sculpting, smoothing, noise and so on > then randomly crashes with the same logs like the author of this thread, sometimes it crashes after 15 seconds and sometimes (maybe twice) I managed to edit for 10 minutes max… Another example, after first time installing UEFN I tried Tilted Towers Template project and in there I was editing terrain too and was experiencing crashes anyways. I reinstalled UEFN once or I deleted local files, nothing helped.