I seem to got same tangent problems in my model. When exporting Normal Map, half of the faces becomes black. I have tried to invert the image and then the other half become black. So It’s either the normals or the tangents, is it a way do fix this after I have done all the sculpting and texturing. The map workes fine as bump, but not as Normal Map. Thanks 
Well, part of the problem is that you’re using Tiles mapping with a tangent map. The mathematics behind tangent mapping mean that you always have a normal flip that takes place when crossing a UV seam. Since Tiles maps have LOTS of seams, you run into trouble. 
That’s not why you’re getting black areas. I can’t answer that question as I’m not a Maya user. But I can promise that you’ll always have trouble using tangent maps with tiles-type mapping. When using tangent maps you really need to be able to hide those UV seams in places where they won’t be noticeable.
Tiled mapping, worked fine for both the displacement, color and bump map and all of them render fine in Maya. But the normal map is stil the same, lots of black spots. It must be the tangents or the normals, but isen’t it a way to fix them in Z-brush?
Normal maps are not like other types of maps. They have their own sets of rules that are completely different from color, bump, or displacement. The rules are also different depending on whether you’re using tangent or object-space maps.
As I explained in my original post, the mathematics that make tangent-type normal maps work are very specific. These mathematics always flip the normals when you cross a UV seam. This is not a ZBrush thing. It’s the nature of that type of map.
The reason why this creates a problem with tiles-type mapping is because AUVTiles and GUVTiles have lots of seams. So the normals flip all over the place.
There is a technique which can compensate for the tangent effect. You can find it here: http://www.zbrushcentral.com/zbc/showthread.php?t=56882 Good luck trying to pull it off with a tiles-type map!
Thanks but I finally got it right Used open configuration > maya best quality tangent space > create normalmap instead of the manually settings with vertical and red channel flip that the tutorial said.
