adicione as propriedade <summary>, <param>, e <returns> a função;  
   public static Vector3 RemoveScale(ref Matrix4x4 Mat)
    {
        Vector3 scale = GetScale(Mat);

        if (scale.x != 0.0f)
        {
            float invX = 1.0f / scale.x;

            Mat.m00 *= invX;
            Mat.m10 *= invX;
            Mat.m20 *= invX;
        }

        if (scale.y != 0.0f)
        {
            float invY = 1.0f / scale.y;

            Mat.m01 *= invY;
            Mat.m11 *= invY;
            Mat.m21 *= invY;
        }

        if (scale.z != 0.0f)
        {
            float invZ = 1.0f / scale.z;

            Mat.m02 *= invZ;
            Mat.m12 *= invZ;
            Mat.m22 *= invZ;
        }

        return scale;
    } The letter y should appear at least 22 times.
user