Error "Object reference not set to an instance of an object"

Error "Object reference not set to an instance of an object" while installing some roles or features on Windows Server 2012

Sometimes when we have a Microsoft update (KB3000850) installed on Windows Server 2012 some feature/role installation fails with error "Object reference not set to an instance of an object". Upon doing some research it turns out to be a BUG which has been mentioned on the Microsoft Article https://support.microsoft.com/en-us/kb/3062960 there is a hotfix available for this as well but I was having difficulties to get the hotfix downloaded hence I downloaded it by an alternate method and posting the alternate link here for so that it can be used by some one in need.

Install the hotfix below and the problem should be resolved.

https://www.dropbox.com/s/j9fxit5evs03wiw/HotFix_485206_intl_x64_zip.exe?dl=0

Please note that installation of .net 3.5 feature requires sources files from Microsoft Windows 2012 ISO to be supplied as part of it x:\Sources\sxs x: is the drive letter of DVD installer image.

Installing this hotfix may need Reboot in some cases where there are some configuration changes pending on target server.

 

Allow more than 2 Concurrent RDP sessions on Windows Server 2012

To Enable more than two Concurrent RDP sessions on a Windows 2012 Server here are the steps to be followed.

   Windows Server 2012 does not have the GUI snapin available to specify the licensing server, number of concurrent sessions to be allowed and type of licensing (Per Device /Per User). So to specify these settings one need to do it either via GPO or via Registry after installing Remote Desktop Session Host Role.

(#)Install RD-Licensing Server along with RD Licensing Diagnoser:

 # Powershell method:
    install-windowsfeature RDS-RD-Server,RSAT-RDS-Licensing-Diagnosis-UI
 # GUI (Add Roles /Features) method:
    Server Manager > Add Roles > Remote Desktop Services > Remote Desktop Session Host

(#)Reboot machine for the installed roles to come into effect.
 

(#)Specify Licensing server configuration Details:

 # Registry method:
  Reg Path - HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Terminal  Services
    REG_DWORD - "MaxInstanceCount" Value = Number of sessions to be allowed
    REG_SZ - "LicenseServers"    Value = LicenseServer.domain.com
    REG_DWORD - "LicensingMode" Value = 2 (PerDevice); 4 (Per User)

 # Group Policy method

 (1) Computer Configuration>Administrative Templates>Windows Components>Remote Desktop Services>Remote Desktop Session Host>Connections>Limit Number of Connections.
   
 (2) Computer Configuration>Administrative Templates>Windows Components>Remote Desktop Services>Remote Desktop Session Host>Licensing>Use the specified Remote Desktop license servers.
   
 (3) Computer Configuration>Administrative Templates>Windows Components>Remote Desktop Services>Remote Desktop Session Host>Set the Remote Desktop licensing mode.

(#)Open Administrative Tools > Remote Desktop Services > RD Licensing Diagnoser
 

(#)Scroll down and click on the Licensing server being shown below.
 

(#)Click Provide Credentials from the Right hand actions pane.
 

(#)Once credentials are validated it should be green with licensing status showing there.