I upgraded Wordpress from 2.2 to see my site display with text and database errors ALL over the place. The database errors said something about there being no "content" category in the DB. I then decided to wipe the entire server account and reinstall Wordpress 2.3 from scratch. Once all of the files were in place, I visited the install URL and saw this: what the freakin hell???? Is the only option to delete the database and start over from scratch? I'll do it if so, but this is really unbelievable.... Thankfully this is for a site that has never been released, or I would have punched a hole in the wall...the bigger problem is my very established Wordpress site that has to get upgraded...I'm really afraid about doing that one...
the problem probably is not the wordpress but the plug-ins you have installed. on the first scenario, maybe you have sitemap plug-in installed. upgrade that first to work for 2.3, then the rest will have no problem.
I disabled all of my plugins before the upgrade (UTW, sitemap, etc). I can't even explain what that was all about I restored my old database, and now things are working. However, I noticed that every single instance where there's an apostrophe in the text, there's now a bunch of characters, like an accented "a", a Euro symbol, and a TM symbol
by just disabling it does not disable DB entry of that plug-in. so the best thing is to upgrade the plug-in first to be compatible.
Its a bad theme, it sounds like. They coded it wrong to look for the specific category tables instead of the method WordPress wants. WP 2.3 changed MySQL table formats. You'll need to contact the theme author or downgrade back to your WP 2.2 install. If you backed up the DB before upgrading, this shouldn't be too much of a problem.
I'm using "Fresh" (the theme). There's a ton of bad code that I'm going through manually - it appears to be working out. The only thing I haven't figured out yet is the blogroll - which shows a bunch of "0"s with two line breaks under each one.