CRM Explorer in Visual Studio 2012 not working with Dynamics CRM 2013 on premise

I am using Visual Studio 2012 and on premise Dynamics CRM 2013, and the Visual Studio template project for Dynamics CRM.  When I click on View> CRM Explorer in Visual Studio, I enter the credentials (CRM discovery user name, authentication details etc).  I then select the Organization from the drop down list - however the window immediately closes and it does not let me select the Solution Name.  Subsequently no CRM Explorer is displayed.

I have seen this posted on this forum and elsewhere without answer.

Another posting stated "We've determined this to be the result of an issue in our CRM2013 environment, although we haven't been able to identify the issue. We installed a new CRM2013 instance, migrated our organization and solutions, and everything works as expected in the new CRM2013 environment."

Has anyone else seen this issue and fixed it?

Thanks alot