Couldn’t find anything in the related questions, so here goes:
I have a post which, when viewed on the site, is returning a redirect loop. The error page is showing an address for the post that originated when the post was added to a category that was subsequently deleted.
www.macrowikinomics.com/innovation-communities/business-economics/will-facebook-be-your-crm-provider is the correct address, but it keeps redirecting to www.macrowikinomics.com/innovation-communities/guest-authors/will-facebook-be-your-crm-provider/. Guest-authors was the old category obviously.
My thought was it might be the automatic canonical URL redirect feature. Despite adding the disable canonical url function (src = Mark Jaquith) it continues to redirect to this old address. Cleared the cache and cookies and still it goes. Tried it in another browser and I continue to get the error. There is also no cache plugin running on the site.
Could it be something in the pretty permalinks? They’re using the format /%category%/%postname%/
Many thanks for any thoughts you can provide.
Do you use a plugin called Redirection? It has a setting that will automatically create redirects when a post permalink is changed, and if the post is renamed and then changed back to the original name, you get a loop. And if a category is removed, WP will reassign a post to the default category and that may be part of it, too.
Also, check .htaccess for any hardcoded 301 redirects.