# itemize/enumerate are throwing a TeX-deactivate-mark issue in Aquamacs

I am using Aquamacs 3.4 in macOS 10.14.3, and have been using Aquamacs for years. When I insert an itemize or enumerate environment into a LaTeX document using C-c C-e, I get the expected prompt:

(Optional) Options (k=v):

If I press RET, then the environment appears in my document. Until today, this would also insert the first \item. Since today (without having updated Aquamacs, macOS, or my LaTeX distribution), I instead get the mystifying status message:

Symbol's function definition is void: TeX-deactivate-mark

What does this message mean? What is going wrong, and how do I fix it and get my \item back? I've tried searching online, but haven't found anything useful regarding TeX-deactivate-mark. C-h v and C-h f in Aquamacs don't seem to know about TeX-deactivate-mark either. I'm not sure whether this is an issue with Aquamacs, AUCTeX, or my LaTeX distribution.

Curiously, M-RET within the environment DOES create an \item as expected.

Thanks for any help; this is my first Stack Exchange post.

UPDATE: In a comment below, @ArashEsbati has helped pin down the problem, and has addressed all of my questions except for "how do I fix it?". As suggested, I entered M-x load-list-path-shadows, which gave an output:

followed by 26 similar lines. Each line involves an item in /Users/.../auctex-12.1.2 "hiding" a corresponding item in /Applications/.../edit-modes. It seems the items in /Applications/.../edit-modes/ are out of date, and are the source of my problem. How do I resolve this conflict? (e.g. is it safe to delete the folder /Applications/Aquamacs.app/Contents/Resources/lisp/aquamacs/edit-modes?)
• This message means that your AUCTeX installation is looking for a function which was removed from AUCTeX in Dec. 2017. I suspect you have multiple AUCTeX's installed on your system. Open your .tex file and trigger the message, then do M-x list-load-path-shadows RET and watch for any duplications. Maybe that gives you an idea. – Arash Esbati Jun 25 at 9:43
• Thank you @ArashEsbati -- this did indeed isolate my problem. See my edits above. (I was not previously aware of list-load-path-shadows, and did not know that TeX-deactivate-mark was removed in 2017.) – k2019 Jun 26 at 14:43
In a comment, @ArashEsbati speculated I had multiple AUCTeXs installed, and suggested trying M-x list-load-path-shadows RET in Aquamacs after triggering the odd status message in a .tex file.
@ArashEsbati was correct: M-x list-load-path-shadows RET revealed that I did indeed have two AUCTeXs installed. I removed one, then found that my .tex files failed to compile with C-c C-c, but DID compile when Aquamacs was loaded without customizations. It seems I inadvertently ruined my ~/Library/Preferences/Aquamacs Emacs/customizations.el file last week; I think this was the ultimate source of my posted problem. At this point it was quicker (for me) to delete all TeX-mode customizations from customizations.el, to delete all AUCTeXs and reinstall Aquamacs, to delete all installed LaTeX distributions, and to download the most recent MacTeX. Works fine now.