A couple of months ago we started work on a multi site wordpress install. Everything was working smoothly. We pushed the codebase up to our staging site with no dramas.
Now a couple of months down the track a funny thing has happened. Multi site is no longer working. Suddenly we can no longer access the sub-domain. No one was sure exactly when it happened, and so it was hard to pinpoint exactly what had happened to cause it to break.
We store backups of all our databases, and as such had a working version of the database.
Now came the ardious task of tralling through data trying to find exactly what was causing the problem.
Ok Sweet, its the wp-options table.
But I looked through all the plugins and we use them on all our wordpress sites. Only, this isnt a normal wordpress site, its multi site.
And the culprit… Root Relative Urls
A WordPress plugin that converts all URL formats to root-relative URLs to enable seamless transitioning between staging/production host environments and debugging/testing from mobile devices, without the use of hackish tactics like textual find-replace strategies or risky hosts/NAT spoofing strategies.
References: 1. http://wordpress.org/extend/plugins/root-relative-urls/