The following error occurs when opening Desktop Studio and accessing the Dashboard tab:
“Database could not be contacted”

In the Desktop Studio Logs, the following error is displayed:
“A database operation failed and could not be recovered: Reason Object reference not set to an instance of an object.”
Note: Apart from these two error messages, there appears to be no other issues and the users are unaffected.

Complete the following steps to resolve the issue:

1. Backup the XenDesktop database.

2. Verify that you can see incorrect Controller reference in desktop studio.

   

   This can also be confirmed by running Get-BrokerController PowerShell command on one of the XenDesktop brokers in the site.

   Example - Correct Entry

   ActiveSiteServices                 : {ControllerReaper, ControllerNameCacheRefresh, Licensing, BrokerReaper...}
   AssociatedHypervisorConnectionUids : {1}
   ControllerVersion                  : 5.6.0.33
   DNSName                            : FQDN
   DesktopsRegistered                 : 2
   LastActivityTime                   : 10/08/2012 10:41:23
   LastStartTime                      : 18/07/2012 21:22:54
   LicensingBurnInDate                : 17/02/2012 00:00:00
   MachineName                        : domain\machinename
   OSType                             : Win32NT
   OSVersion                          : 6.1.7601.65536
   SID                                : S-X-X-XX-XXXXXXXXX-XXXXXXXXX-XXXXXXXXX-XXXXX
                                        158
   State                              : Active
   Uid                                : 1
   
   Example - Incorrect Entry
   ActiveSiteServices                 : {}
   AssociatedHypervisorConnectionUids : {}
   ControllerVersion                  :
   DNSName                            :
   DesktopsRegistered                 : 0
   LastActivityTime                   :
   LastStartTime                      :
   LicensingBurnInDate                :
   MachineName                        : S-X-X-XX-XXXXXXXXX-XXXXXXXXX-XXXXXXXXX-XXXXX
   OSType                             :
   OSVersion                          :
   SID                                : S-X-X-XX-XXXXXXXXX-XXXXXXXXX-XXXXXXXXX-XXXXX
   State                              : Off
   Uid                                : 2

3. Follow this procedure to remove any incorrect broker from the site - Add, remove, or move Controllers, or move a VDA.

4. Run Get-BrokerController command to verify that the incorrect Controller reference is removed from the database.

5. Open Desktop Studio and verify that there are no errors while accessing the Dashboard tab.

Problem Cause

The problem occurs when joining a new Controller to a Site fails half-way through. This leaves the database in an inconsistent state.

CTX128075 - XDDBDiag for XenDesktop
CTX127969 - Desktop Studio Logging Options for XenDesktop 5