WMTS Addition Problem

All,

I am having problems getting Geocortex (SL 1.8, Essentials 3.12) to recognise my WMTS service.  So, to test that it wasn't my server I tried to hit a known endpoint that works within ArcCatalog.  This doesn't work:

http://v2.suite.opengeo.org/geoserver/gwc/service/wmts

The response is:

The URL 'http://v2.suite.opengeo.org/geoserver/gwc/service/wmts' does not appear to reference a valid WMTS map service. Underlying error: Failed to get the capabilities from URI http://v2.suite.opengeo.org/geoserver/gwc/service/wmts

I assume when making this request that it actually the GC application services making the call back on the server, rather than up on the client?

Regards,

Matt