xmpp output plugin exception

Hi,

I'm trying to send messages from logstash. In logstash.conf I have written:

output {
xmpp {
host => "talk.google.com"
message => "Helloooooo"
user => "username"
password => "password"
users => "other_account@gmail.com"
}
}

But after execute:
elmanytas@elmanytas-trusty:~/Downloads$ java -jar logstash-1.3.2-flatjar.jar agent --verbose -f logstash.conf

The agent says:
D, [2014-01-07T08:31:54.433000 #8560] DEBUG – : Debugging mode enabled.
W, [2014-01-07T08:31:54.434000 #8560] WARN – : Warnings mode enabled.
D, [2014-01-07T08:31:54.436000 #8560] DEBUG – : CONNECTING:
talk.google.com:5222
D, [2014-01-07T08:31:54.551000 #8560] DEBUG – : SENDING:
<stream:stream xmlns:stream='http://etherx.jabber.org/streams' xmlns='jabber:client' to='elmanytas' xml:lang='en' version='1.0' >
D, [2014-01-07T08:31:54.618000 #8560] DEBUG – : RECEIVED:
<stream:stream from='elmanytas' id='62G0CD9B48467158' xmlns:stream='http://etherx.jabber.org/streams' version='1.0' xmlns='jabber:client'/>
D, [2014-01-07T08:31:54.634000 #8560] DEBUG – : FEATURES: waiting...
D, [2014-01-07T08:31:54.643000 #8560] DEBUG – : RECEIVED:
<stream:features><starttls xmlns='urn:ietfarams:xml:ns:xmpp-tls'><required/></starttls><mechanisms xmlns='urn:ietfarams:xml:ns:xmpp-sasl'><mechanism>X-OAUTH2</mechanism><mechanism>X-GOOGLE-TOKEN</mechanism></mechanisms></stream:features>
D, [2014-01-07T08:31:54.650000 #8560] DEBUG – : FEATURES: received
D, [2014-01-07T08:31:54.654000 #8560] DEBUG – : FEATURES: waiting finished
D, [2014-01-07T08:31:54.657000 #8560] DEBUG – : SENDING:
<starttls xmlns='urn:ietfarams:xml:ns:xmpp-tls'/>
D, [2014-01-07T08:31:54.720000 #8560] DEBUG – : RECEIVED:
<proceed xmlns='urn:ietfarams:xml:ns:xmpp-tls'/>
D, [2014-01-07T08:31:54.724000 #8560] DEBUG – : PROCESSING:
<proceed xmlns='urn:ietfarams:xml:ns:xmpp-tls'/> (REXML::Element)
D, [2014-01-07T08:31:54.725000 #8560] DEBUG – : TRYING stanzacbs...
D, [2014-01-07T08:31:54.726000 #8560] DEBUG – : TRYING message/iq/presence/cbs...
Exception in thread "LogStash::Runner" org.jruby.exceptions.RaiseException: (NoMethodError) undefined method `error' for nil:NilClass
at RUBY.to_s(file:/home/elmanytas/Downloads/logstash-1.3.2-flatjar.jar!/xmpp4r/errors.rb:43)
at RUBY.accept_features(file:/home/elmanytas/Downloads/logstash-1.3.2-flatjar.jar!/xmpp4r/connection.rb:111)
at RUBY.connect(file:/home/elmanytas/Downloads/logstash-1.3.2-flatjar.jar!/xmpp4r/connection.rb:79)
at RUBY.connect(file:/home/elmanytas/Downloads/logstash-1.3.2-flatjar.jar!/xmpp4r/client.rb:70)
at RUBY.connect(file:/home/elmanytas/Downloads/logstash-1.3.2-flatjar.jar!/logstash/outputs/xmpp.rb:56)
at RUBY.register(file:/home/elmanytas/Downloads/logstash-1.3.2-flatjar.jar!/logstash/outputs/xmpp.rb:36)
at org.jruby.RubyArray.each(org/jruby/RubyArray.java:1613)
at RUBY.outputworker(file:/home/elmanytas/Downloads/logstash-1.3.2-flatjar.jar!/logstash/pipeline.rb:213)
at RUBY.start_outputs(file:/home/elmanytas/Downloads/logstash-1.3.2-flatjar.jar!/logstash/pipeline.rb:145)
elmanytas@elmanytas-trusty:~/Downloads$

Thank you for your help

Cheers,

Jose Manuel