Why do I get this error while trying to create a 3rd landscape in world composition?

I was finally able to fix one error but now this one comes up. Before i was able to create up to nine landscapes(with 4 max to be visible at once in the editor) but now i get this error when i try to create a third landscape underworld composition.

Assertion failed: SizeX <= GetMax2DTextureDimension() [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Windows/D3D11RHI/Private/D3D11Texture.cpp] [Line: 570] Requested texture2d x size too large: 32768, 16384

I came here with the same exact problem/question… A real bummer it’s been almost a month and not a single answer. I posted a similar question at forums.unrealengine.com and no answer. Did you ever happen to figure it out?