I am pretty sure this is caused by the TexMod dll injection conflicting with THUG PRO's dll injection. Also, it has nothing to do with OpenGL because PC THPS games use DirectX.
You see, THUG PRO uses dll injection for updating and engine modifications which would be impossible otherwise. Also, THUG PRO had integrity checks added in some update. Most likely in case the update screws up or someone decides to modify the scripts.