title: Connecting to Team Foundation Server (TFS) with proxy authentication
body: <p>Yesterday I created a new project in Codeplex. I created a connection from Visual Studio to the TFS server I was assigned and uploaded my solution successfully. Today I'm trying to connect again to the Codeplex TFS server to work on the solution. When I try to open it, I get the error:</p>
  
  <blockquote>
    <p>Team Foundation Server
    <a href="https://tfs06.codeplex.com/" rel="nofollow noreferrer">https://tfs06.codeplex.com/</a> does not
    exist or is not accessible at this
    time.</p>
    
    <p>The remote server returned an error:
    (407) Proxy Authentication Required.</p>
  </blockquote>
  
  <p>The corporate environment I'm using does use proxy authentication but this wasn't an issue yesterday. Any ideas on why it worked then and how to make it work now?</p>