Tried setting up a CesiumTerrainProvider this morning and kept getting the following error:
XMLHttpRequest cannot load http://assets.agi.com/stk-terrain/world/layer.json. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8080' is therefore not allowed access. The response had HTTP status code 503.
I even attempted to look at the terrain in Sandcastle on the Cesium website, which also does not work:
When you load the terrain sandcastle it appears as if there is no globe, but if you zoom out far enough you'll see a transparent globe and an error in the console about a problem loading the terrain.
Is this being looked into?