Comment 1 for bug 1368269

I also have seen this error, once the node is ready.

2014-09-11 11:34:15-0400 [ClusterClient,client] Amp server or network failure unhandled by client application. Dropping connection! To avoid, add errbacks to ALL remote commands!
 Traceback (most recent call last):
   File "/usr/lib/python2.7/dist-packages/twisted/protocols/amp.py", line 913, in ampBoxReceived
     self._commandReceived(box)
   File "/usr/lib/python2.7/dist-packages/twisted/protocols/amp.py", line 892, in _commandReceived
     deferred.addCallback(self._safeEmit)
   File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 306, in addCallback
     callbackKeywords=kw)
   File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 295, in addCallbacks
     self._runCallbacks()
 --- <exception caught here> ---
   File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 577, in _runCallbacks
     current.result = callback(current.result, *args, **kw)
   File "/usr/lib/python2.7/dist-packages/twisted/protocols/amp.py", line 924, in _safeEmit
     aBox._sendTo(self.boxSender)
   File "/usr/lib/python2.7/dist-packages/twisted/protocols/amp.py", line 577, in _sendTo
     proto.sendBox(self)
   File "/usr/lib/python2.7/dist-packages/twisted/protocols/amp.py", line 2153, in sendBox
     self.transport.write(box.serialize())
   File "/usr/lib/python2.7/dist-packages/twisted/protocols/amp.py", line 551, in serialize
     "Unicode value for key %r not allowed: %r" % (k, v))
 exceptions.TypeError: Unicode value for key '_error_code' not allowed: u'CannotRemoveHostMap'