Ouch,ya my guess is he was experimenting or such, and clearly that is what occurred, problem likely solved.
Lesson learned in this case I suspect, and always just use built in terrain function which can easily create that which he has shown, but if he wants to use blender he still can as it has a nice terrain plugin which gives interesting results ( free, comes with blender), but if that’s used you need to do a slightly complex procedure as in set it up correctly, and render it via black and white blended ramp ( 16 bit png) which works fine in ue4.
I’ve not done it in awhile, but that’s the idea, and there are tutorials for creating heightmaps in blender :
https://www.youtube.com/watch?v=K5E1Rh0v4pk ,is the most thorough one I could find atm and worth watching for other ideas as well.
Not sure he mentions it as I didn’t watch all of it, but as long as you export 16bit PNG, it should come into ue4 just fine, and I"ve had good luck doing so here.