It may be related to this -

iOS devices (iPhone, iPad etc) have no concept of a mouse pointer or mouse-over. Therefore sites exported with versions prior to MX required the site visitor to click on a button once to see the mouse over and a second time to invoke the link. This his has been changed in MX so that the first tap will always follow the link.
But Pierre's links do not work on IOS or Android tablets.

To upload your .XAR file you can attach the file to a post after clicking "Reply" and "Go Advanced"