Error in Posting (WP 2.5)

Hello,

I’ve upgraded to WP and everything was fine until I needed to make a post. I was trying to save it and it didn’t work, so I try publishing it. Both of them would yield an error.. with a bunch of codes.

In fact, you’d get the error even when you try to click on a post.

I did try disabling all plugins, and the problem still exists.

Any suggestion what I should do? Thanks ahead of time!