XeCycle <xecycle@gmail.com> writes:

> replace-in-string is a compiled Lisp function in
> `color-theme.el'.
>
> (replace-in-string TARGET OLD NEW)
>
> So...  F**ked up.  Anyway to force mm-replace-in-string use the one from
> gnus?

It looks your color-theme.el is too old.  There is a change not defining
replace-in-string, which is available in 6.6.0 release:

http://bzr.savannah.gnu.org/lh/color-theme/trunk/revision/55

Anyway, I'll install the attached fix in Gnus side as well since mml2015
usage of mm-replace-in-string does not really need the 4th arg.