Holy Crap Batman! So it appears they are using the IE shell extensions to load a webpage from the launcher.

If you have an older version of IE that has notoriously bad ECMAScript (JS) support which loads a page requiring a file hosted by a third party which can update / change the version outside of the control of Squenix (Google CDN Hosted) you are going to have a bad time. This is just bad design on their part by using the assumption because it is windows that all windows users have IE installed and all windows users keep their PC updated.