“I wish I never upgraded my Wordpress to the newest version, the Wordpress 2.3.” That’s what I said after upgrading my Wordpress engine.

Upgrading immediately your Wordpress software to the latest version is really the best thing to do especially if tons of security bugs are corrected with that latest version. However, upgrading your Wordpress to the version 2.3 immediately without upgrading your plugins and themes, will really pissed you off.

Just recently, I upgraded my Wordpress without reading the upgrade note nor the posts of bloggers who recently upgraded their own Wordpress. After 5 minutes setup with the use of an FTP client, I then tried to post new write-ups, and then Wordpress told me this:

WordPress database error: [Table ’selaplan_wordpress1.wp_post2cat’ doesn’t exist]
SELECT cat_ID AS ID, MAX(post_modified) AS last_mod FROM `wp_posts` p LEFT JOIN `wp_post2cat` pc ON p.ID = pc.post_id LEFT JOIN `wp_categories` c ON pc.category_id = c.cat_ID WHERE post_status = ‘publish’ GROUP BY cat_ID

This message appear even if you will just post your comment.

So, what should you do?

(1) Not yet upgraded

If you haven’t yet upgraded your Wordpress but are planning to upgrade it to Wordpress 2.3, do the following:

1. Read the Wordpress note to make prepare yourself in upgrading your Wordpress system and follow their instructions as quoted:
   • Back up your blog. It never goes out of style, and we have a nifty Codex page with a few different methods.
   • Check for the latest versions of your plugins. Here’s a list of known compatible and incompatible plugins with 2.3, Google Sitemaps seems to be one causing a lot of issues. (Forum thread.) Upgrading might get you cool new features anyway. Don’t forget about our plugin directory.
   • Enjoy the last time you have to check for plugin updates manually, as 2.3 will do it magically behind the scenes.
   • Read up on how to modify your theme to add tag support.
   • Consider switching your install to use Subversion to make updating ultra-easy.
   • Make a list of your friends who are less computer literate so you can help them upgrade. (Maybe throw an upgrade party?)
2. Install the “Upgrade Preflight Check” Wordpress plugin and activate it, then create a report in order for you to identify the cause of errors. Download the plugin here.
3. If you think your blog is ready for the upgrade then upgrade now. Download the latest version of Wordpress here.

(2) Upgraded already

If you upgraded your Wordpress already and don’t experience any problems with it, then good for you. However, if you experienced what I experienced, then try the following:

1. Check if you are using the “Google Sitemaps” plugin. If you are using it, then deactivate it. Most of the Wordpress users who experienced similar problems found out that it’s the “Google Sitemaps” plugin that caused the errors. Download the latest version of it that is compatible with the newest version of Wordpress. Download here.
2. If the problem exist after disabling or upgrading the “Google Sitemaps” plugins, then try deactivating all your plugins that are not listed here. This is the list of plugins that are compatible with the Wordpress 2.3.

So, next time before you upgrade your Wordpress system, be sure to read first the upgrade notes to avoid any problems.