I'm getting error with my Rig

Hello !
I don’t know if it’s the right place to post my issue, but here it is.
I’m trying to animate this rig :
IKEA
Problem is that when I try to animate it, with Animation Editor, it shows me this :
ERROR
I’m using this : https://www.roblox.com/library/2908380847/Rig-Editor to make my joint
What is the problem? I can provide screen of the joint

Can u provide a screenshot from the explorer which leads to all the parents and children from the rig? It will be clearer and easyer for me to solve your problem.

Tip:
Try to use Moon Animator.
It’s a more powerful tool that can keyframe also properties, try to use the plugin. If you don’t know how u use it watch the tutorial from YouTube. There are many different videos.
Or you can read this topic: Getting Started with Moon Animator 2 - [Unofficial]