Recently we have noticed an increase in the number of customers that claim Vanity URLs are not working.  We have yet to find an issue with Vanity URLs other than not being configured correctly.  It also seems that most of these reports are coming from users stating they are running IIS7 and receiving a 404 error when accessing a vanity url.  Below are some of the common items that users have overlooked while configuring Vanity URLs.

• The first clue that you have not configured vanity urls is if you receive a 404 error page.
  This means that the Active Social Vanity URL handler is not receiving the request at all.  The Active Social Vanity URL handler will never generate a 404 message.  Instead, it will redirect the user to the search page for either members or groups if it can't locate the appropriate page for the requested vanity url.
  
  
• Running IIS 7 under classic mode.
  Even if you are running IIS 7, your app pool might be running in classic mode.  If you are running in classic mode then you need to follow the instructions for configuring Vanity URLs under IIS 6 or ask your hosting provider to switch you app pool to Integrated Mode.
  
  
• Failed to update web.config file properly.
  As described in the setup instructions, the modules section under system.webServer in your web.config file must have the  runAllManagedModulesForAllRequests="true" attribute in place.  You also must have preCondition="managedHandler" included with the entry for the SocialRewriter.
  
  
• Another module is blocking the request.
  For best results, the SocialRewriter entry in your web.config must be the first item listed in the modules section.  Otherwise it is possible for another module to intercept the request and cause the 404 error.

Special Note for DotNetNuke 5.6.0
DotNetNuke 5.6.0 includes a new featured called AutoAliasMapping.  There are few issues with this feature that can affect Vanity URLs.  You can follow the steps below to update the ErrorPage.aspx file to circumvent these problems until DotNetNuke 5.6.1 is released.

1. Open ErrorPage.aspx  with a normal text editor. 
2. Add the following code just below the form tag:
   
   < %

           If Request.QueryString("error").Contains("IX_PortalAlias") Then

               Response.Redirect("~/Default.aspx")

           End If

       % >
3. Save the file