title: Visual Studio 2013 cannot connect SQL Server when second instance of VS is opened
body: <p>I have a strange problems with my Visual Studio (2013 Professional). I'm using SQL Express 2014 and the built in IIS Express on the same machine for a project, and my code works fine in debug mode until I start a second instance of the Visual Studio with a different project opened. From that point the debugging in the first instance stops working, and when I start it I get the following exception:</p>
  
  <p>"A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)]"</p>
  
  <p>It is clearly not a network related (no network involved) and instance specific error (SQL server works fine under usual conditions). Could anyone tell me what is the problem with Visual Studio?</p>
  
  <p><strong>UPDATE:</strong> I tried to recreate the problem, and I realized that the other opened project is mapped to the same IIS virtual directory and the same port, which implies this problem has nothing to do with SQL connectivity, so the question lost its relevancy. I assume when you use IIS Express VS updates the IIS configuration when you open a project. However I still don't understand why I get an SQL exception (EF5, Code-first, database initialization), when the code is starting up. If someone could explain this, I'll give the bounty.</p>