ctr-z glitch?

While working, I accidentally moved one of the walls in my game and pressed ctr-z to move it back-
it moved the wall back where it was, but it also removed the actor's animation and all of it's clone's animations (10-15 of them)
I was using a sequence, and the sequence no longer shows up in the actor's list of animations (so I cant apply it to the actors again) yet when I try to replace the sequence with another identical one, it doesn't show up either
I didn't save and rebooted the program, but the animation still doesn't show up-
anyone had this problem?
any way to fix it?
it moved the wall back where it was, but it also removed the actor's animation and all of it's clone's animations (10-15 of them)
I was using a sequence, and the sequence no longer shows up in the actor's list of animations (so I cant apply it to the actors again) yet when I try to replace the sequence with another identical one, it doesn't show up either
I didn't save and rebooted the program, but the animation still doesn't show up-
anyone had this problem?
any way to fix it?