For anyone using the XMPie’s Circle tool within Chrome (which has never been the most stable platform for using Circle) will now no longer get the opportunity to try because in April 2015 officially removed the support for Microsoft SilverLight (and other Netscape API based plugins).

It is potentially possible to work around this (until September 2015, when everything is removed) by visiting the hidden configuration page in Chrome: 

chrome://flags/#enable-npapi

However this will also be removed in September 2015 – so is only a stop-gap resolution.

Until XMPie moves Circle away from a old-technology base users are going to have to use FireFox, Safari or Internet Explorer it would seem.