Captivate 9 - IE 11 - Publishing as HTML5 Only

Receiving:

The content you are trying to view is not supported in the current Document Mode of Internet Explorer.  Change the Document Mode to Internet Explorer 9 Standards and try to view the content again.

To change the Document Mode, press F12, Click Document Mode, and then select Internet Explorer Standards.

I have some people receiving this, they are using IE11.  If I publish the file as HTML5/SWF the courseware launches, however, we don't want to publish as HTML5/SWF.  Other people can launch just fine with IE11.

Anyone have any thoughts as to why it won't work for some?

Thanks