Wind Serpent Fury bugged

henever I cast Wind Serpent Fury (last tier of spear's skills) my game crashes and I get the error message and my game crashes :
Error: Metadata/Effects/Spells/spear_serpentstrike/snakeImpact_01.ao is non-virtual and does not have a physical file

I tried running steam's verify files and reinstall the game and I sill have the issue. It doesn't happen always, but around 70% of the times

here's a screenshot of the error: