title: How to fix request failed on channel 0
body: <p>When I want to connect to my server like this</p>
  
  <pre><code>ssh -a username@my-server.de -p 22
  </code></pre>
  
  <p>it gives me two error messages:</p>
  
  <pre><code>PTY allocation request failed on channel 0
  shell request failed on channel 0
  </code></pre>
  
  <p>When I use the parameter <code>-T</code> the first error message goes away.
  But how to fix the second one?
  I can't connect. To other servers I can connect without any problems.</p>
  
  <p>I'm on MAC OS 10.9.</p>
  
  <p>The parameter <code>-v</code> shows me this debug output:</p>
  
  <pre><code>OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011
  debug1: Reading configuration data /etc/ssh_config
  debug1: /etc/ssh_config line 20: Applying options for *
  debug1: Connecting to xxx.your-server.de [188.40.3.15] port 22.
  debug1: Connection established.
  debug1: identity file /Users/xxx/.ssh/id_rsa type -1
  debug1: identity file /Users/xxx/.ssh/id_rsa-cert type -1
  debug1: identity file /Users/xxx/.ssh/id_dsa type -1
  debug1: identity file /Users/xxx/.ssh/id_dsa-cert type -1
  debug1: Enabling compatibility mode for protocol 2.0
  debug1: Local version string SSH-2.0-OpenSSH_6.2
  debug1: Remote protocol version 2.0, remote software version mod_sftp/0.9.8
  debug1: no match: mod_sftp/0.9.8
  debug1: SSH2_MSG_KEXINIT sent
  debug1: SSH2_MSG_KEXINIT received
  debug1: kex: server-&gt;client aes128-ctr hmac-md5 none
  debug1: kex: client-&gt;server aes128-ctr hmac-md5 none
  debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024&lt;1024&lt;8192) sent
  debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
  debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
  debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
  debug1: Server host key: RSA 55:f5:ca:ca:01:45:0f:7b:71:0a:1f:ba:9e:25:17:fb
  debug1: Host 'xxx.your-server.de' is known and matches the RSA host key.
  debug1: Found key in /Users/xxx/.ssh/known_hosts:1
  debug1: ssh_rsa_verify: signature correct
  debug1: SSH2_MSG_NEWKEYS sent
  debug1: expecting SSH2_MSG_NEWKEYS
  debug1: SSH2_MSG_NEWKEYS received
  debug1: Roaming not allowed by server
  debug1: SSH2_MSG_SERVICE_REQUEST sent
  debug1: SSH2_MSG_SERVICE_ACCEPT received
  debug1: Authentications that can continue: publickey,password
  debug1: Next authentication method: publickey
  debug1: Trying private key: /Users/xxx/.ssh/id_rsa
  debug1: Trying private key: /Users/xxx/.ssh/id_dsa
  debug1: Next authentication method: password
  </code></pre>
  
  <p>After I enter the password, I get this:</p>
  
  <pre><code>debug1: Authentication succeeded (password).
  Authenticated to xxx.your-server.de ([xxx.xxx.3.15]:22).
  debug1: channel 0: new [client-session]
  debug1: Entering interactive session.
  debug1: Sending environment.
  debug1: Sending env LANG = de_DE.UTF-8
  shell request failed on channel 0
  </code></pre>