Restore from backup?
1. What does “Manage | Categories” say?
2. 2.3 has no tag management screen. You add/edit/remove tags in the Write Post screen.
“Something strange happened. Try refreshing the page.”
When I try to add a category but nothing happens when i refresh
Aye, your category table is probably gone. Restore it from backup.
I forgot to make a backup so all my categories are gone, which is not a big problem just is there anything I can do to ever be able to add categories again?
The categories are not gone. I had same error after the upgrade from 2.3, but was able to convert the categories to tags. Unfortunately new added categories will not show up in the category-list. Seems a bug so far.
I have not tried to do a fresh install of WordPress 2.5.
