This error can be cause by following reasons:

• No correct Url's in the configuration file named "Web.config";
• No correct Primary and/or Backup ELAS DB paths in the configuration file named "Web.config";
• Any other error in the configuration file named "Web.config";
• If there are some problems with Primary and/or Backup ELAS DB Servers;
• Some of the both ELAS Authentication Web Service and ELAS Web Administration Tool Web Service is unavailable;
• Unhandled exception has occurred in the application.

For more information check ELAS Log, please! The ELAS Log is placed in Windows Event Log available this way Start->Control Panels->Administrative Tools->Event Viewer->ELAS.

Ask your system administrator for more information how to solve the problem, please!