WordPress Upgrade Failure and Lessons Learned

The long awaited WordPess 3.0 came out today and I was excited to upgrade all of my WordPress sites. This version of WordPress offers a lot of great new features and I had been running the release candidate version on this site without any problems. Until today….

So I started by upgrading all of my personal sites first. No problems. Then I move on to the busiest site I run, El Iluminador.com. I was a bit skeptical at first and thought maybe I should wait until the weekend. We had just released a bunch of new articles yesterday so the site was getting some pretty steady traffic. But since I hadn’t run into any problems on any of the other sites, I thought, “What the heck.”

I logged into the back end and did a database backup. I then clicked on the “Upgrade” button and held my breath. I got the “Upgrade is successful” message, hit the Dashboard button and guess what I see….

Fatal error: Call to a member function add_rewrite_tag() on a non-object in ../wp-includes/taxonomy.php on line 289

Great….

So I’ve learned (the hard way) that errors that appear like this, after an upgrade, are usually caused by a plugin. So I backup the plugins folder and I’m getting ready to nuke it. But then I think, maybe I should Google the error code first and see what pops up.

I first come across this post on WordPress.org which talks about a problem in the “podcast” folder. I’ve got that folder since I use that plugin for the LBCast. Then the post then sends me to this post which talks about an error with the Podcasting Plugin by TSG and how to fix the code.

I delete the “podcast” folder on my web server and the site comes up again. Whew…. crisis adverted! I then fix the code, re-upload the file, and everything is back to normal again.

Lessons Learned:

• Always back up your site before you do an upgrade, especially the database
• Deactivate all plugins before you upgrade (something I didn’t do)
• After you upgrade, activate the plugins one by one to make sure none of them cause any errors
• If you activate a plugin and the site goes down, you know which plugin caused it
• And if you run into a problem, Google is your best friend

Photo found via Flickr.