Poor Quality Ligh Map and Missing Textures

I am having a problem generating a good quality light map for mobile use. The map darkens the entire scene and has a large pixels showing. Also for some reason the trees in the scene do not have the texture applied when I use the light map but the hedges seem OK. The tree models are there but the texture is not being displayed.

I have done several tutorials on light maps but can not seem to get this to work.

What am I doing wrong here? any and all advice is welcome.

This is the scene without the light map:

This is the scene with the light map:

“…and there was much rejoicing!” I managed to figure this out.

I was scaling the set models as the originals are very small. I was computing the light map with the scaled up models. Once I returned the model to it’s original size the dark pixels disappeared when I built the light map. I then scaled the model up and it looks fine.

The tree texture issue was a bit different, it seems not all the shaders work with the light maps. Some do some do not. I had to play around with them to find something that worked.