According the IE11 console error reference:
"HTML1113: Document mode restart from [mode] to [mode]
The webpage requires a different document mode than the browser was
currently set to.
This message can occur when the user browses from another page, so it can be out of the developer's control."
Given your description, it sounds like your child frame is embedded within a larger document. If that's the case, verify that the document modes of both document are consistent. If one requires standards mode, the other should be using it as well.
For best results, use the HTML5 doctype (<!DOCTYPE html>
) for all documents; this will trigger standards mode (or edge mode, as it's now called) in each version of IE. If you're not able to do this, then you may wish to try opening the framed document in a new window, rather than embedding it on a parent document.
Hope this helps...
-- Lance