Recently, when creating a new post I found that I'm unable to add tags to my posts. When I click the add button, the page refreshes and no tags are added. Also, when i type in a tag in the field, no tags previously used tags are suggested. Similarly, in my old posts, the tags don't show up in the editor (though they are still at the bottom of the published posts).
At first I thought it was an issue because I hadn't upgraded to 3.3.1 (I had a similar experience before upgrading to 3.3 and that solved itself upon upgrading).
I have tried deactivating all my plug ins, but that changed nothing.
This is very frustrating. Can anyone help?