Hi everyone, I think I have a tough question.
I had a base character with 9 animations, all working.
Then I went back to the meshes for few days to add more details to the costume so that the character looks less basic.
Finally I got back playing the animations to see how the new meshes deform with the animations, and at that point about half of the animations no longer work.
By "no longer work" I mean that no matter what frame I choose on the timeline, absolutely no bone move. If I manually move a bone and key a few new frames for it, the bone won't move either, just keeping the last position I moved it to.
It's like something prevents blender to apply the bone transformations on few of my animations.

I noticed something that hopefully will make sense to someone. I opened the graph editor and I noticed that for those animations that work, the graph editor has lines with bright colors, whereas for those animations that don't play, the graph editor shows lines as well but they are in muted color, a lot like disabled.

Does anyone know what could do that to an animation?
Blender is not always the most intuitive application, some suggestions would be so welcome.

thanks in advance

Ok, in the action editor there is a menu option under Channel > "Revive Disabled F-Curves"
I don't really know what that is but that work. Should I be worried about it?