I made a whole lot of mates in an assembly, about 30 of them, when I noticed I did one with the wrong part.  So I went toi the tree and deleted the 3 wrong ones.  The part wouldn't move out of the way.  So I tried Edit / undo, expecting one mate to be removed.

But what happened was I got to watch EVERY one of them get undone, like a movie.  Nothing would stop it.  And Re-do is greyed out!!!!

Is there any way to get them back?  Other than starting over?

Ahhhh!!