Playing 2 custom animations at once in custom player model?

Just before start, I am using the Roblox animation script.

I've made my own custom player models that are fully animated (Jumping, Running, walking, crouching etc.) and when one animation is playing it works great, but when it comes to play 2 animations the older animation does not work at all, I did not make any mistakes like not naming last keyframe "End" or looping my animation. It should play 2 Animations at once, but for some reason it does not. So here's my question : Is this possible to play two or more custom animations at once in custom player model? And if yes, then can someone tell me how? (If there's need I will post my edited Roblox animation script)

You can disable certain body parts to not be affected by an animation. If you don't, even if you don't edit them in any way they will still behave as if they are animated. With certain body parts disabled, you can run another animation at the same time as another. However, the animation with the highest priority will override the other if the same parts are being animated.