KBI 310140 Invalid HostName Issue In Business Manager


All Versions Of Argent Business Manager


29 Jan 2009


Argent Business Manager may not load properly when hostname with “_” (Underscore) is specified in the URL. This will work fine with “localhost” or IP address of the machine.

This Microsoft issue is only visible in Internet Explorer 6 and above. Firefox will resolve hostnames with underscores and work perfectly.

Technical Background

This is a Microsoft issue where underscores are not allowed in host names by RFC 952 and may interfere with the ability to set cookies and thus to persist sessions.

Microsoft considers host name with “_” (Underscore) as Bad Host Name. Hence browser does not accept cookies if host name contains the underscore character “_“.

Microsoft Internet Explorer 6.0 and above cannot accept any domain names with underscore characters and session cookies cannot be saved. This will result in terminations when navigating within Web pages.


As per Microsoft, if your host name contains an invalid character such as “_” you need to gain access to the site by using the IP address instead of the name, or change the host name to a valid name.

Additional information on this Microsoft issue: