Build Lighting Fail - Need Serious Help

Hello guys, im having a major issue with my lighting build, i have made a single terrain level of the size 255 x 255 quads, 1x1 selection and 32 x 32 number of components + Fill World. Now my lighting wont build, either it takes too long with preview settings or if i choose medium light quality it still wont complete lighting, it still says (“lighting not built, 1024 unbuild objects”)

any help?

could you post some screen shots of the result your getting and what lighting you have in the scene?

Things to check off the top of my head:

Have you got a lightmass importance volume?
Have you got a sky light in the scene?
Check your light setting to make sure they are all correct. i.e. is intensity set to zero or 999999 (which will cause issues)
Check the material you have on the landscape, do you have too many textures or is the normal cranked up REALLY high.

Can probably help better once i can see what is actually happening.