Normal map appear dark without details cycles

I retopo my high poly sculpt, created UV map, selected the high poly object first, than the low poly (so the low poly is the active one), bake normal map (cycles used, so I had a texture image node selected), than apply normal map as in picture:


this is how appear the low poly models without normal map (note normal map texture node muted)


As you can see when apply normal map the model turn black, without details. I tried to add a texture coordinate node, on UV, as suggested on here (http://blender.stackexchange.com/questions/48958/object-turns-dark-when-using-normal-map-in-cycles), but don’t work.

not only the model turn very dark but need very strong light to illuminate it.

Maybe I doing something wrong with normal map creation? Anyway the map is here.

here you can download the scene and the normal map

Thanks in advance for your help and sorry for my poor enghlish.

Try setting the strength of the normal map back to 1

Thanks for the fast reply.
On pictures normal map strength is se to 10 only because I don’t know what parameter change, so tested as much as possible. Anyway even to 1 no details and too dark, going down with normal strength become more bright but still zero details added by normal map

Strange, very strange, this issue made me crazy for a week, restart blender this morning and now totally disappear! All normal details are here, didn’t change anything, simple reopen the saved file.