Sometimes, when you change the Emacs version and you have own or custom Emacs packages installed and compiled with the previous version you may get unexpected behavior, including invalid function c-point warning message. The best solution for this is recompiling your *.el files using the current Emacs version:

Remove all old *.elc pre-compiled files:

find site-lisp/ -name "*.elc" -print | xargs rm -f

Recompile all Emacs source code files:

emacs --batch --eval "(byte-recompile-directory \"site-lisp/\" 0)"