> From: Reuben Thomas <rrt@sc3d.org>
> Date: Tue, 11 Oct 2016 16:41:17 +0100
> Cc: 24640@debbugs.gnu.org
>
> Is it possible to disable this loading of undo-tree history? If so,
> can you disable it and see if Emacs no longer crashes? If the crashes
> stop when undo-tree history is not loaded, we will have to look
> closely at what that loading does, because the problem is probably
> there. The internals of undo changed in Emacs 25.
>
> Yes, the crashes appear to stop when I comment out (global-undo-tree-mode) in vars.el.
OK, so we have our prime suspect. Can you tell where I can find the
exact version of undo-tree-mode you are using?