major.io words of wisdom from a systems engineer

Upgraded to WordPress 2.7

I’ve upgraded the blog successfully to WordPress 2.7 (with a bit of frustration). When I attempted the upgrade, I received this error:

Call to undefined method wpdb::has_cap() in schema.php on line 22

Even though I followed the instructions on the WordPress site, and I disabled all of my plugins, the error kept appearing. The only parts of the site that remained unchanged after the upgrade were the wp-config.php page and the wp-content directory. I merged the changes in wp-config.php, but the error was still present.

In frustration, I renamed the wp-content directory to a temporary name and uploaded the wp-content provided from the WordPress tarball. The upgrade completed without a problem! I deleted the new wp-content directory, put the old wp-content directory back in place, and WordPress sprang to life!

It’s certainly possible that a WordPress plugin blocked the upgrade process even though it was disabled in the database.