Found that I have this issue right now too. Windows 8, IE11, latest Xenforo 1.4.5. The filename says jquery-1.11.0.min.js
Still no editor in IE. Is there any option to fix it.
Not that I plan to use IE - just to make things work smooth for all types of users..
As I presume it's working correctly here for you, I'd recommend posting in troubleshooting with as much info as possible. Please do test with add-ons disabled and the default style (and the default language) to eliminate variables.