Crash when using both tessellation and virtual texture on a landscape material

When a landscape is set up to use runtime virtual texturing.

If it uses a material that writes to a runtime virtual texture and has tessellation enabled.

Then we see a crash and the log reports:

Shader expected a uniform buffer of struct type LandscapeContinuousLODParameters at slot 3 but got null instead. Rendering code needs to set a valid uniform buffer for this slot.

This was reported in:

https://udn.unrealengine.com/questions/555013/renderer-crash-in-4242-with-virtual-texture-materi.html

Open TM-RuntimeVirtualTextures map in QAGame project

Open Landscape_RVT_Mat material

Set the D3D11Tessellation property on the material to "Flat Tessellation"

Observe the crash