Insufficient privileges - The current logged on user does not have administrative access to the Web server

Error Message

When using the ArcGIS Server .NET Manager on Vista or Windows Server 2008, the application unexpectedly errors with one of the following messages:

"Insufficient privileges - The current logged on user does not have administrative access to the Web server.
Administrative access is required for creating and editing Web applications.
Please contact your system administrator for further assistance."

"Session has expired. Session variable for ArcGISServer couldn't be retrieved."

"An error has occurred on the server. For details please check the Event (Application) log on the web server.
The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security."

Cause

The application domain that Manager is using in IIS 7 restarted unexpectedly.

Solution or Workaround