wp-admin/post.php?action=edit&post=0

I type a post and then when I click save or save and continue editing, my post goes blank and my url reads this

wp-admin/post.php?action=edit&post=0

I have created previous posts and they still work but none of the new ones. I have read about deactivating plugins but don’t know how.

I haven’t added anything new that might cause these problemsa and am using a 2.2 edition.