Call to a member function add_rewrite_tag() on a non-object
July 9, 2010 – 2:14 am |This is an addendum to our WordPress Upgrade Woes article that was previously published.
During upgrade of one of our blogs, we ran into the “Call to a member function add_rewrite_tag()” error and it raised some alarm, but we quickly found a support forum thread on the subject.
It turns out that a couple of different plugins are responsible for this specific error message to come up immediately after upgrading to 3.0. The plugins we have found so far that cause this error are:
- Lifestream plugin
- Mailpress_MailingList
- podcasting – How to fix – this “fix” is a little hacky
- wordtube – so far only older versions reportedly causing this issue
- wp-e-commerce (aka WP Shopping Cart)
The way to see which plugin is causing your error is to:
- FTP to your server and rename your plugins directory to something like _plugins (similar to these instructions)
- log into your WordPress site.
- This will cause all of the plugins to be deactivated.
- one by one, activate your plugins.
- If the page loads and shows you the plugins list, then it was not the plugin that you just activated.
- If you see the error again, then you know which plugin is causing the problem.
- Just rename your plugins directory again and refresh your plugins page.
At this point, it would probably be best to contact the plugin author in order to get them to fix the plugin. Do not reactivate the offending plugin until you update it, or else you will be stuck again.
If you find any other plugins that are causing this error, please report it in the comments so we can add it to this list.
