Basically I had 22 categories on my WP. The host has some kind of DDoS attack and when my site was back up again, none of my categories are showing up. All my 900 posts are now uncategorised I clicked on categories on WP backend and it it says "You do not have sufficient permissions to access this page." If I go to Dashboard and chose categories (still showing 22 categories on Dashboard), once it is open, there is nothing there. Is there a way to fix this quickly? I do not want to add the categories back again and then recategorised each post one by one. It would take me forever. Please help. Thank you.
Sounds like a database issue. The quickest way to resolve this would be to restore a backup. Did you back up your database at all before this attack? I'd recommend using this plugin and set it to backup at least weekly: http://wordpress.org/extend/plugins/wp-db-backup/ I'm also confused as to why it would say "You do not have sufficient permissions to access this page." -- are you sure you're logged in as an administrator?
Yes it was a database issue and luckily I got it fixed without needing to restore backup as I didnt backup for the past 4 days. I've never been able to access the categories on the back end ever, I can do it using dashboard no problems. Just not straight on catagories.