I am unable to add a new category for posts. I don't get any error message -- just nothing happens when I hit "Add." Also cannot delete any existing categories. Trying to delete gets "An unidentified error has occurred."
I am running 3.2.1 multi-site. I have tried deactivating all plugins, with no result, and have changed themes, also with no result. Using different browsers doesn't help. I have also tried adding an .htaccess file to wp-admin, as recommended in other posts.
Any help would be greatly appreciated. I desperately need to edit my categories!