I installed ArcGIS for Server 10.1 (uninstalled version 10 and installed) and tried to create new site after the installation with ArcGIS Server Manager that popped up. I created primary site administrator account, specified root server directory and configuration store, then clicked Finish button. Error message was on Configuration Summary dialog box. "Failed to create the site. Failed to create the folder 'System'. Failed to clear REST cache onone or more server machines. Please check the log for more details." What is the cause of these problems and how do I solve these issues?