When attempting to logon using Windows Authentication instead of Forms, the followin message is displayed:
"We are sorry, there has been an error in Archive Manager.
Please contact your administrators and help desk and report this error."
The URL has been changed to
http://archivemanagerServername/Error.htm?aspxerrorpath=/Default.aspx
User is not mailbox-enabled
Create a mailbox for the user account in question or use a mailbox-enabled account to logon to the Archive Manager website.