I read your post, and as I mentioned, I watched the video. So did the programmer of the Spriter plug-in, and we both ended up with a totally different theory of what you're trying to make happen and what the problem might be.
I dare say you have not watched the video carefully, because I have shown everything in detail.
1- is it related to the character?
Yes. You can see the difference between the "working" version and the "not working" version in the video. I even drew hints on the screen, so you can see exactly what works and what doesn't. I wonder if you downloaded the source project.
2- if so, are you trying to make it have like a rag-doll death behavior?
That's exactly what I'm trying to do. As you can see, Spriter has some kind of bug that causes the character to somehow fold and start twitching all over the screen. By the way, this is accompanied by an insane drop in game performance, up to the point of crashing.
3- did you apply some kind of physics to the body part images or the bones of the sprites that the Spriter object is using?
Yes, in the video you can see that before I start ragdoll, I pause the animation and then turn on the physics behavior of the whole character sprite. I showed 2 cases, in one it works fine, in the other it doesn't work at all, and the working way is a big crutch, which shouldn't be there.