This error occurs if QualityCenter.getTestSetLogFiles() returns null. This can happen if the tests did not run due to some error (which was my fault (again, see JENKINS-12389)) on the jenkins slave.

ERROR: Publisher com.michelin.cio.hudson.plugins.qc.QualityCenterResultArchiver aborted due to exception
java.lang.NullPointerException
at java.util.ArrayList.addAll(ArrayList.java:472)
at com.michelin.cio.hudson.plugins.qc.QualityCenterResultArchiver.perform(QualityCenterResultArchiver.java:81)
at hudson.tasks.BuildStepMonitor$3.perform(BuildStepMonitor.java:36)
at hudson.model.AbstractBuild$AbstractRunner.perform(AbstractBuild.java:682)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildSteps(AbstractBuild.java:657)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildSteps(AbstractBuild.java:635)
at hudson.model.Build$RunnerImpl.post2(Build.java:161)
at hudson.model.AbstractBuild$AbstractRunner.post(AbstractBuild.java:604)
at hudson.model.Run.run(Run.java:1400)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:175)