Object edges turn gray, cant edit properly

[yaschan]

Edit poly in one of the objects in scene doesnt work properly. Edges turn gray and almost impossible to see them.

I can select polys edges or verts, but I cant use cut, swift tool and most of the tools at all.

The edges turn gray and  I see strange white outlines as in the screen shot.

I tried export this object as fbx and reimport but same happens.

What am I missing?

Flip the polys silly.