Walk SWEP not working

Well the an Walk SWEP I downloaded has recently stopped working I think because of an animation update for GMod.

To be exact the SWEP still slows me down and removes the weapon in first person.

But it doesn’t look like a walk, because the player model hands are in a “pistol” type position (Third person).

I checked the console to see any errors and this is what I’ve received.

“Bad pstudiohdr in GetSequenceLinearMotion()!”

Any assistance will be appreciated.