Well that was a ride. Spent all day trying to do an upgrade from Wordpress 2.5.0 to 2.6, only to run into the “White Screen of Death” over, and over again. I couldn’t get into anything - the blog index, the admin panel, nothing. As it turned out, there was two different issues to be dealt with.

First, as pointed out by Colin McNulty in amazing detail over at his blog (http://www.colinmcnulty.com/blog/2008/07/08/solution-to-wordpress-blank-screen-of-death/), the automated Wordpress upgrade.php script appears to add an extra line in the wp-config.php file. A single extra blank line causes most of these problems. Remove this line manually, and you can once again access your admin panel, where you’ll be able to fix the second problem, if you still can’t read the index of your blog. It may just be stupid of me, but I forgot to backup my theme folder when I upgraded - WordPress was still trying to use the theme I had on there prior to the upgrade, which was missing. So simply go to the Admin Panel, and revert back to the default wordpress theme. Or, I guess, you could just re-upload the old theme if you managed to back that up and all.