@Paul Do you have similar config? I use it to enable flycheck in editing 
temp src buffer.


    (defadvice org-edit-src-code (around set-buffer-file-name activate
    compile)
       (let ((file-name (buffer-file-name)))
         ad-do-it
         (setq buffer-file-name file-name)))


On 12/22/2017 06:39 AM, Paul Davis wrote:
>
> Turns out that the issue was caused by trying to disable a flycheck 
> checker using the org edit src hook
>
>
> On Mon, Dec 18, 2017, 6:30 AM Nicolas Goaziou <mail@nicolasgoaziou.fr 
> <mailto:mail@nicolasgoaziou.fr>> wrote:
>
>     Hello,
>
>     Paul Davis <paul.dangersalad@gmail.com
>     <mailto:paul.dangersalad@gmail.com>> writes:
>
>     > Using ~C-c '~ to edit a src block works as expected, but if I make
>     > changes and use ~C-c '~ again, I get the error ~Cannot modify an
>     area
>     > being edited in a dedicated buffer~
>
>     I need more information. Where do you make changes? In the newly
>     created
>     buffer? Where do you call ~C-c '~?
>
>     For example, I created the following buffer
>
>         #+begin_src emacs-lisp
>           (+ 1 2)
>         #+end_src
>
>     moved on the source block, used C-c '. Then, in the new buffer,
>     I replaced 2 with 3 and pressed C-c ' again, without any error?
>
>     IOW, could you provide a precise recipe demonstrating the issue?
>
>     Thank you.
>
>     Regards,
>
>     --
>     Nicolas Goaziou
>