title: Unable to login to private docker registry
body: <p>I am trying to login to a private docker registry (Artifactory) using the following command</p>
  
  <pre><code>docker login myserver:myPort
  Username: myUser
  Password:
  email: me@myServer.com
  </code></pre>
  
  <p>This fails with the following error</p>
  
  <pre><code>Error response from daemon: no successful auth challenge for https://myserver:myPort/v2/ - errors: []
  </code></pre>
  
  <p>Note that I have forced authentication for the docker repository that I am trying to access.
  I am on Docker version 1.9 Here is the <code>dokcer info</code></p>
  
  <pre><code>Containers: 0
  Images: 20
  Server Version: 1.9.1
  Storage Driver: aufs
   Root Dir: /var/lib/docker/aufs
   Backing Filesystem: extfs
   Dirs: 20
   Dirperm1 Supported: false
  Execution Driver: native-0.2
  Logging Driver: json-file
  Kernel Version: 3.13.0-24-generic
  Operating System: Ubuntu 14.04 LTS
  CPUs: 4
  Total Memory: 1.955 GiB
  </code></pre>
  
  <p>and docker version </p>
  
  <pre><code>Version:      1.9.1
  API version:  1.21
  Go version:   go1.4.2
  Git commit:   a34a1d5
  Built:        Fri Nov 20 13:12:04 UTC 2015
  OS/Arch:      linux/amd64
  
  server:
  Version:      1.9.1
  API version:  1.21
  Go version:   go1.4.2
  Git commit:   a34a1d5
  Built:        Fri Nov 20 13:12:04 UTC 2015
  OS/Arch:      linux/amd64
  </code></pre>
  
  <p>What does the error mean?</p>