закомментировала вызов do_feed в плагине magic fields 2, помогло
у меня такая же проблема с задвоением
Use Xpost Infobox Widget, at the post page in admin you see Xpost block this settings
Resolved. My problem was in php.ini:
mbstring.func_overload = 2
mbstring.internal_encoding = UTF-8
This need to comment out.
I tried all, no results.
If it is important – text cyrillic.
