Light Build Error

Hi folks

I’m completely new to UE… I’ve installed the 64-bit version and I’ve been playing around with it. If I add lighting actors, or change existing lights in template projects, on pressing Play I get a ‘Lighting needs to be rebuilt’ warning. If I attempt to build all levels, or the lighting specifically, I get this error:

lighting-build-error1.png

Shouldn’t UE’s internal components that will allow me to build the lighting, work with the 64-bit version? What do I need to do to fix this?

I’m using UE 4.14.3 on a 64-bit Windows machine, if that makes any difference.

Cheers!

Yikes! Has no-one seen this before?