After upgrading to a new version of Archive Manager, the website loads the default webpage, or displays a 400 level error.
When Archive Manager was initially installed, a different host header was entered.
These settings from original installation are used during the upgrade process.
The original host header has been written into IIS on the Archive Manager Server.
Open up IIS on the Archive Manager Server
Right Click the Archive Manager website and click properties.
On the first screen tab, click the Advanced Button.
Change the host header to the correct address by clicking Edit.
Next go to a command prompt and type "IISRESET" and hit enter.
The website should load properly now.