UE4 Crashing & Deleting Landscape Actor (World Composition)

I have used World Creator 2 to create a tiled heightmap that, with all tiles combined, is 20.165km x 20.165km (~407km squared). Each tile is exported at 4033m x 4033m (resulting in 25 tiles grouped 5x5)

I import into UE4 using World Composition with “Enable Edit Layers” selected because I need to actually edit the landscape after import. Once done importing everything, a single landscape actor exists for all 25 tiles.

I load in 3 of the levels and enter into landscape mode to perform a test sculpt and UE4 crashes with the following error:

[File:D:/Build/++UE4/Sync/Engine/Source/Runtime/RenderCore/Private/RenderingThread.cpp] [Line: 907]
Rendering thread exception:
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

First, I don’t know how it’s getting 32768, 16384. My map is nowhere near those dimensions. Are they even dimensions?

Second, there’s no texture on the landscape. It’s the default checkered pattern you see when no texture is applied… therefore, I have no idea why it’s saying a texture is requested.

Third, when UE4 crashes, it DELETES THE LANDSCAPE ACTOR! This is a big problem because when I reload UE4, it’s gone and no further editing of the landscape is possible. When I enter into landscape mode, there is a message in a red box stating:

“Landscape actor is not loaded. It is needed to do layer editing”.

Is there any way to recreate the landscape actor once it’s removed during a crash? Is the removal of the actor normal?

Is my only option to delete all the levels and re-import them again, crossing my fingers every time I try to edit the landscape and pray UE4 doesn’t crash again?

Am I completely doing this all wrong and showing how new I am to UE4 (been tinkering for a couple months)? I’m really hoping I’m doing something wrong and someone can make me feel stupid. I’d really like to not have to shrink the map size down further.

Thanks for reading!