How to stop Shadow Seams/Bleed ?

Hi guys

I am trying to create modular walls, however, I can’t seem to get the light/shadows to work correctly. See screenshot below. The squares are the modular static mesh, and you can see sharp changes from one mesh to another.

[According to this - there doesn’t seem to be a way around this. Is that right? Is there some way to force a single CPU thread to process?][1]

Covered by Tim Hobson here