Weird "Waves" on mesh with Armature Modifier

Hello guys,

apparentlz weight painting really hates me.
I have been building my rig for some time now, and suddenly a weird eroor appeared:
though i tried to smooth the weight painting, all the vertexes are somehow deforming very strange.
I have no idea what it could be, i tried everything i knew…
This is what i mean:

I have inserted the file if someone wants to take a look.
I hope you will help me t.t

bj1.blend (1.84 MB)

Thank you!!

Did you try Automatic Weights first - this is my preferred technique, it gives you a very good first pass that you can tweak afterwards. I am not sure why you need such a high spec Sub-surf Mod and a Smooth Mod at all given the number of vertices in your model… Try un-parenting, removing Armature Mod, deleting Vertex groups and strutting again with Automatic Weights and see where you get to.

Work on a copy of your project of course in case you really FUBAR everything.

Cheers, Clock.