We updated Jenkins from 1.424.1 till 4.471 yesterday, and now Jabber notifications aren't working.
It doestn't work only in downstream jobs, if one depends from another one. In the last job in stream notification always sends.

there is an exeption in console output:
ERROR: Publisher hudson.plugins.jabber.im.transport.JabberPublisher aborted due to exception
java.lang.NullPointerException
at hudson.plugins.im.IMPublisher.notifyChats(IMPublisher.java:530)
at hudson.plugins.im.IMPublisher.notifyOnBuildEnd(IMPublisher.java:303)
at hudson.plugins.im.IMPublisher.perform(IMPublisher.java:290)
at hudson.tasks.BuildStepMonitor$3.perform(BuildStepMonitor.java:36)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:717)
at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:692)
at hudson.model.Build$BuildExecution.post2(Build.java:183)
at hudson.model.AbstractBuild$AbstractBuildExecution.post(AbstractBuild.java:639)
at hudson.model.Run.execute(Run.java:1509)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:236)