The CKEditor Files need to be updated to version 4.3.1 which has had IE 11 bugs addressed.
in the webassist/ folder, rename the ckeditor folder to ckeditor_bak
On this page:
click the button to launch CK Builder. Select to use the Full Preset, and the Kama Skin.
Copy the downloaded CKEditor folder to the webassist folder in your site.
from the ckeditor_back folder, copy the following three files:
and paste them in the new ckeditor folder.
Since you are using the Power CMS Version of Design Extender with live edit:
-rename the ckeditor/config.js file to cofig_orig.js
-in the ckeditor_back folder, copy the config.js and past it to the new ckeditor folder.
-ckeditor_back/plugins folder copy the cms_source folder and past it to the new ckeditor/plugins folder
you will need to clear the browsers cache to see the updates take effect.