There’s a null reference there somewhere, it has nothing to do with your GPU drivers or when the last time you restarted. Unreal’s Landscape code is getting something it’s not expecting and crashing. Maybe the Landscape Spline component doesn’t have any spline points in it or something?
We can’t tell exactly what’s happening since you don’t have the symbols. So the first step you should do it install the Editor’s symbols, then when it crashes you’ll see which line and function it’s crashing in which might give you a better hint of what’s going wrong, which data it’s expecting. You’ll then be able to just read Unreal’s source code for more info.
See this post for instructions on downloading the debugging symbols: