Description
This error occurs when you do not have administrative privileges to the ArcGIS Server machine (the host machine name) that you specified.
Solution
ArcGIS Server uses the operating system's users to determine who can connect to and administer the server. Consult your systems administrator to determine if you have administrative access to the server. If you want to do this by yourself, use the operating system tools to examine whether you are part of the ArcGIS Server administrators group (agsadmin) on the server object manager machine.