I saw yesterday that WordPress 3.0 was out of beta and available via WordPress’s terrific automatic update feature.  I figured if they had it available through that, they must have worked out any auto install bugs, right?

Well, not quite.

I did the auto install on my personal blog and was told that it failed, then when I tried to go back and change some things in my admin, I got this error:

Fatal error: Call to undefined function set_current_screen() in /xxxxx/wordpress/wp-admin/admin.php  on line 129

I did a little digging around and discovered that I wasn’t the only one.  The suggestions were to disable all your plugins (if you don’t have admin access you can do this by simply renaming the plugins directory via FTP) and see if that works, which would mean one of your existing plugins was causing the issue, or do a manual upgrade.

Renaming my plugins directory didn’t fix it for me, so I decided to do the manual upgrade, and that did the trick.  My WordPress 3.0 blog is working peachy keen now.

There’s a lot going on in WordPress 3.0 and I was eager to play with it, but it was pretty late at that point so I messed with the new default WordPress theme, Twenty Ten, a little bit and called it a night.

While the manual install isn’t particularly difficult, I’m not going to suggest our clients upgrade to it yet unless they want to give it a go themselves.  I’m going to wait until whatever bugs there are in automatically upgrading from WordPress 2.9.2 to WordPress 3.0 are fixed before we go forward with that.

In case you want to know how to manually upgrade from WordPress 2.9.2 to WordPress 3.0, here are the steps:

• Download WordPress 3.0 and unzip the files into the WordPress folder on your computer.
• Back up your database.  This is optional, but it’s a good idea.
• Disable your plugins.  Sometimes a plugin will conflict with something in a newer version of WordPress.  You can reactivate them one at a time to make sure there’s no conflict.  I usually skip this step, personally, but I do remember once or twice where it caused me a problem.
• Delete the wp-admin and wp-includes directories on the server.
• Upload all the WordPress 3.0 files to your server except the wp-contents folder.  That folder contains your themes and plugins.
• Upload the wp-content/themes/twentyten folder.  This will give you the WordPress 3.0 default theme, Twenty Ten, which lets you use all of WordPress 3.0’s new features.  Uploading this folder separately from the rest will ensure that any other themes or plugins you have are not overwritten.
• You’ll be prompted to update your database, which takes under a minute, then you’re done and ready to explore the new features of WordPress 3.0!