I upgraded this blog and now my permalinks structure causes 404 errors.
I have reverted this to use WordPress Default, and am not using permalinks at the moment.
I am investigating the sql file and my (very few) plugins but I don’t know if the issue is there. I think it may have to do with rules for Lighttpd. Using lighty has been a struggle really, especially when you encounter errors, because at the back of my mind I often wonder if it has something to do with it.