Problem with Dark shadows / dark spots

[ClockworkOcean]

I noticed this post, does it help?

Weird shading on deform mesh

Fixed it by enabling “Force all skinned meshes to recompute tangents”. But wait! Some hard shading appeared on mesh… [Screenshot_1] Now how i fix that?! Also, on my whole model UV seams look like hard edges, but in blender i don’t have anything like that. [Screenshot_2] What is going on?