World Terrain disapeared

Hello all!

Is there some thing wrong with WorldTerrain server? If you try to open any example in Sandcastle, you can’t see the Globe, only black sky and stars. There is an Error in console:

Failed to load resource: the server responded with a status of 504 ()
Failed to load No ‘Access-Control-Allow-Origin’ header is present on the requested resource. Origin ‘’ is therefore not allowed access. The response had HTTP status code 504.


For example:


the same error is happening to me aswell:

No 'Access-Control-Allow-Origin' header is present on the requested resource.

Is there something wrong?

Dana četvrtak, 6. rujna 2018. u 09:40:26 UTC+2, korisnik Andrey Orlov napisao je:

Same here: Cesium Ion is down. Impossible to login

Same here,
Also, cannot log-in to the Cesium-ion account.

My guess: it is under server-maintenance. T.T

Hello everyone,

First off, I’m sorry I missed this post yesterday or I would have replied much sooner.

As you already know, there was a partial unintended outage of ion that took place from Thursday September 6th 3am EST and lasted for about 3 hours. Specifically, the issue was with our API server, While the server never actually went down; connectivity issues with our back-end database led to the inability to sign in or request access tokens. Obviously this is something we take very seriously and have already tracked down the issue to a race condition in newer code that only happened under heavy server load (which is probably how it made it through our internal testing). At the same time, we identified an issue with our health checks that caused the failing server to stay up instead of failing over to a new instance. This has also been addressed and we are in the process of deploying both of these fixes to our production servers so I don’t expect this problem to happen again.

I would like to thank each of you for reporting this outage and please let us know ASAP if you experience any similar problems in the future, either through the forum, or reporting an issue in our ion GitHub repository:

We are also planning to put together a formal status page/twitter account so that we can make the community aware of any possible issues in the future. Feel free to follow this issue if you would like to be notified when it is ready:

Thanks again,


As a final follow up, our new incidents and status page is now live at

We opted to not create a twitter account at this time, but if enough people request it we will revisit the issue.

Thanks again,