19:42:19 ERROR: Build step failed with exception

19:42:19 java.lang.NullPointerException

19:42:19 Caused: com.google.common.util.concurrent.UncheckedExecutionException

19:42:19 at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2234)

19:42:19 at com.google.common.cache.LocalCache.get(LocalCache.java:3965)

19:42:19 at com.google.common.cache.LocalCache$LocalManualCache.get(LocalCache.java:4764)

19:42:19 at jenkins.security.UserDetailsCache.loadUserByUsername(UserDetailsCache.java:127)

19:42:19 at hudson.model.User$UserIDCanonicalIdResolver.resolveCanonicalId(User.java:1319)

19:42:19 at hudson.model.User$CanonicalIdResolver.resolve(User.java:1256)

19:42:19 at hudson.model.User.get(User.java:465)

19:42:19 at hudson.model.User.getOrCreateByIdOrFullName(User.java:626)

19:42:19 at hudson.model.User.get(User.java:607)

19:42:19 at hudson.plugins.clearcase.ucm.UcmActivity.getAuthor(UcmActivity.java:247)

19:42:19 at jenkins.scm.RunWithSCM.calculateCulprits(RunWithSCM.java:138)

19:42:19 at hudson.model.AbstractBuild.calculateCulprits(AbstractBuild.java:341)

19:42:19 at jenkins.scm.RunWithSCM.getCulprits(RunWithSCM.java:96)

19:42:19 at hudson.model.AbstractBuild.getCulprits(AbstractBuild.java:330)

19:42:19 at jenkins.scm.RunWithSCM.calculateCulprits(RunWithSCM.java:133)

... several times
hudson.model.AbstractBuild.calculateCulprits(AbstractBuild.java:341)

19:42:19 at jenkins.scm.RunWithSCM.getCulprits(RunWithSCM.java:96)

19:42:19 at hudson.model.AbstractBuild.getCulprits(AbstractBuild.java:330)

19:42:19 at jenkins.scm.RunWithSCM.calculateCulprits(RunWithSCM.java:133)

19:42:19 at hudson.model.AbstractBuild.calculateCulprits(AbstractBuild.java:341)

19:42:19 at jenkins.scm.RunWithSCM.getCulprits(RunWithSCM.java:96)

19:42:19 at hudson.model.AbstractBuild.getCulprits(AbstractBuild.java:330)

19:42:19 at hudson.tasks.MailSender.getUserEmailList(MailSender.java:455)

19:42:19 at hudson.tasks.MailSender.createEmptyMail(MailSender.java:389)

19:42:19 at hudson.tasks.MailSender.createBackToNormalMail(MailSender.java:204)

19:42:19 at hudson.tasks.MailSender.createMail(MailSender.java:195)

19:42:19 at hudson.tasks.MailSender.run(MailSender.java:112)

19:42:19 at hudson.tasks.Mailer.perform(Mailer.java:171)

19:42:19 at hudson.tasks.BuildStepCompatibilityLayer.perform(BuildStepCompatibilityLayer.java:81)

19:42:19 at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:20)

19:42:19 at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:744)

19:42:19 at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:690)

19:42:19 at hudson.model.Build$BuildExecution.post2(Build.java:186)

19:42:19 at hudson.model.AbstractBuild$AbstractBuildExecution.post(AbstractBuild.java:635)

19:42:19 at hudson.model.Run.execute(Run.java:1840)

19:42:19 at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)

19:42:19 at hudson.model.ResourceController.execute(ResourceController.java:97)

19:42:19 at hudson.model.Executor.run(Executor.java:429)

19:42:19 Build step 'E-mail Notification' marked build as failure

19:42:19 FATAL: java.lang.NullPointerException

19:42:19 java.lang.NullPointerException

19:42:19 Caused: com.google.common.util.concurrent.UncheckedExecutionException

19:42:19 at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2234)

19:42:19 at com.google.common.cache.LocalCache.get(LocalCache.java:3965)

19:42:19 at com.google.common.cache.LocalCache$LocalManualCache.get(LocalCache.java:4764)

19:42:19 at jenkins.security.UserDetailsCache.loadUserByUsername(UserDetailsCache.java:127)

19:42:19 at hudson.model.User$UserIDCanonicalIdResolver.resolveCanonicalId(User.java:1319)

19:42:19 at hudson.model.User$CanonicalIdResolver.resolve(User.java:1256)

19:42:19 at hudson.model.User.get(User.java:465)

19:42:19 at hudson.model.User.getOrCreateByIdOrFullName(User.java:626)

19:42:19 at hudson.model.User.get(User.java:607)

19:42:19 at hudson.plugins.clearcase.ucm.UcmActivity.getAuthor(UcmActivity.java:247)

19:42:19 at jenkins.scm.RunWithSCM.calculateCulprits(RunWithSCM.java:138)

19:42:19 at hudson.model.AbstractBuild.calculateCulprits(AbstractBuild.java:341)

19:42:19 at jenkins.scm.RunWithSCM.getCulprits(RunWithSCM.java:96)

19:42:19 at hudson.model.AbstractBuild.getCulprits(AbstractBuild.java:330)

19:42:19 at jenkins.scm.RunWithSCM.calculateCulprits(RunWithSCM.java:133)

19:42:19 at

... several times

hudson.model.AbstractBuild.calculateCulprits(AbstractBuild.java:341)

19:42:19 at jenkins.scm.RunWithSCM.getCulprits(RunWithSCM.java:96)

19:42:19 at hudson.model.AbstractBuild.getCulprits(AbstractBuild.java:330)

19:42:19 at hudson.model.AbstractBuild$AbstractBuildExecution.post(AbstractBuild.java:639)

19:42:19 at hudson.model.Run.execute(Run.java:1840)

19:42:19 at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)

19:42:19 at hudson.model.ResourceController.execute(ResourceController.java:97)

19:42:19 at hudson.model.Executor.run(Executor.java:429)