CVS Tagging plugin currently does not work with CVS Plugin 2.0 or later.

SEVERE: Executor threw an exception
java.lang.NoSuchMethodError: hudson.scm.CVSSCM$DescriptorImpl.getCvsExeOrDefault()Ljava/lang/String;
at hudson.plugins.cvs_tag.CvsTagPlugin.perform(CvsTagPlugin.java:89)
at hudson.plugins.cvs_tag.CvsTagPublisher.perform(CvsTagPublisher.java:117)
at hudson.tasks.BuildStepMonitor$3.perform(BuildStepMonitor.java:36)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:798)
at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:770)
at hudson.model.Build$BuildExecution.cleanUp(Build.java:192)
at hudson.model.Run.execute(Run.java:1620)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:237)