I can use my style file under 23.1, 23.4, but after I update Emacs to 24.1, I can’t use the old style files. For example, one of my style files is color-theme-arjen.el.

In my elisp file, I use following code to load the color theme:

(load-file “~/emacs/site-lisp/color-theme/master_color-theme-arjen.el”) (color-theme-arjen)

I don’t know why the color theme works under Emacs 23.1 & 23.4 but just doesn’t work under Emacs 24.1.

While Emacs is loading the file, Emacs gives following error:

Symbol’s function definition is void: plist-to-alist

If I uncomment above code and don’t load the style file, the error is dismissed.

Why this happens? Here is the answer:

The color theme stuff was heavily revamped in 24, there is a color theme package included with emacs (see M-x customize-themes), and as far as I know breakage of older themes is expected.

The color theme package from marmalade reportedly works as well.

It seems that the only solution is to open a bug report for color-theme-arjen if I want to use the old theme. So I use M-x customize-themes to find my best theme right now.