This error is returned by API server when the global per service limit is exceeded. It may happen that multiple users are accessing the service at the same time causing it to reach its capacity, or few users sending enormous amount of requests. Likely, we're already aware of this happening and working on the problem, or the problem is short term and will resolve in 15 minutes. If you think you need more capacity than system can handle please contact Scrapinghub sales department.