Adding site binding gives object null reference error in IIS7

Recently I have tried to add new binding to the my existing site using IIS GUI. But when fill the relevant information and click ok button its ended up with prompting object null reference to me.

 

But I could not find solution for this but found the another way to do the same task using Appcmd.exe(only available in IIS 7 or above). I want to add new net.tcp biding to the site and I ran below code in the command prompt(please make sure to run comman prompt as Administrator mode- other wise there will be another errors.).

appcmd set site /site.name: contoso /+bindings.[protocol='https',bindingInformation='*:443:'].