Works perfectly with xUnit 1.14, but after upgrading to 1.16:
[xUnit] [INFO] - Starting to record.
[xUnit] [INFO] - Processing CppUnit-1.x
[xUnit] [ERROR] - The plugin hasn't been performed correctly: Unable to serialize hudson.FilePath$FileCallableWrapper@b749a3

And from the Main Jenkins log:
WARNING: Publisher com.thalesgroup.hudson.plugins.xunit.XUnitPublisher aborted due to exception
java.lang.NullPointerException
at com.thalesgroup.hudson.plugins.xunit.XUnitPublisher.perform(XUnitPublisher.java:230)
at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:19)
at hudson.model.AbstractBuild$AbstractRunner.perform(AbstractBuild.java:624)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildSteps(AbstractBuild.java:603)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildSteps(AbstractBuild.java:581)
at hudson.model.Build$RunnerImpl.post2(Build.java:160)
at hudson.model.AbstractBuild$AbstractRunner.post(AbstractBuild.java:550)
at hudson.model.Run.run(Run.java:1386)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:145)
Feb 27, 2011 2:13:18 AM hudson.model.AbstractBuild$AbstractRunner performAllBuildSteps
WARNING: Publisher hudson.plugins.warnings.WarningsPublisher aborted due to exception
java.lang.NullPointerException
at hudson.plugins.warnings.WarningsPublisher.perform(WarningsPublisher.java:237)
at hudson.plugins.analysis.core.HealthAwarePublisher.perform(HealthAwarePublisher.java:281)
at hudson.tasks.BuildStepMonitor$2.perform(BuildStepMonitor.java:27)
at hudson.model.AbstractBuild$AbstractRunner.perform(AbstractBuild.java:624)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildSteps(AbstractBuild.java:603)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildSteps(AbstractBuild.java:581)
at hudson.model.Build$RunnerImpl.post2(Build.java:160)
at hudson.model.AbstractBuild$AbstractRunner.post(AbstractBuild.java:550)
at hudson.model.Run.run(Run.java:1386)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:145)
We are running Jenkins master/slave build environment structure, e.g. all builds are running on Windows/Linux based slaves.
Now all jobs, which are using xUnit failed.