I'm trying to get Emacs 24.3.1 to open the *Backtrace* buffer on errors, but nothing I try seems to do the trick. This includes evaluating (setq debug-on-error t), running the toggle-debug-on-error command, and verifying that there is nothing in my .emacs that could be influencing it.
Errors always get printed to the mini-buffer, but even when I manually open *Backtrace, it doesn't show any of the debugging info.
Any thoughts on how I can restore the expected functionality?
You can imagine that, as Emacs 24.3 has been available for quite a while, many people use debug-on-error with it, with no problem.
You do not provide a recipe starting from emacs -Q (i.e., not init file). If you can give us such a recipe to reproduce the problem then we can try to address that. Unless you do that, we can only assume that the problem comes from your init file (or from some code that it loads).
Without knowledge of that code, we cannot really help much, except to suggest ways to find the problem introduced by your init file. How to find a bug in .emacs or init.el should help with that.