Need to see the error, screen the box and post it here.
here's the screenshot
UE4 errors are hard to diagnose, it could be anything. Usually it due to graphics or drivers. Make sure you have the latest video card drivers, (do a clean install) and try it. Try with v-sync on and off fiddle with the graphics settings. If you can narrow it down to a single option that may be causing it, let us know.
OK... after approx 8hr of playing, the crash with "fatal errors" occurred quite often. I can't tell what triggered the crashes as they happened at quite random. I'm still enjoying the game though