I have started using engine-mode for emacs and I love it. For some reason though the Amazon search engine does not work properly. I have used the same structure as advertised in the github website
(defengine amazon
"http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=%s")
and when I try to search for anything emacs returns a "engine/execute-search: Invalid format operation %%D" error. All the other search engines worked flawlessly, and I couldn't find anyone with the same complaint online. I assume there might be some issue with the % signs in URL's?
Thanks in advance for any help on this.
Quoting @VanLaser solution, just use "https://www.amazon.com/s/ref=nb_sb_noss?field-keywords=%s"