Anybody know whats wrong with the normals? so why its flashing? 
This will be a website in a view years!
MFG
This could be a problem with autosmooth kickin in and out. Try decreasing or increasing the “deg” value in editbuttons.
If that doesn’t help, you could post your .blend so we can have a look.
I will try the deg button.
Here s a pic from where the arm could come out:
But i think it s not that good…
Maybe your mesh got duped?