Paul Ferraro created WFLY-6265: ---------------------------------- Summary: ClassNotFoundException when creating singleton service via SingletonPolicy Key: WFLY-6265 URL: https://issues.jboss.org/browse/WFLY-6265 Project: WildFly Issue Type: Bug Components: Clustering Affects Versions: 10.0.0.Final Reporter: Paul Ferraro Assignee: Paul Ferraro Fix For: 10.1.0.Final This is because the org.wildfly.clustering.singleton.SingletonPolicy interface references org.wildfly.clustering.service.Builder from the org.wildfly.clustering.service module, but this module is not exported to deployments. {noformat} &amp#27;[0m&amp#27;[31m13:22:08,386 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-5) MSC000001: Failed to start service jboss.deployment.unit."singleton.war".INSTALL: org.jboss.msc.service.StartException in service jboss.deployment.unit."singleton.war".INSTALL: WFLYSRV0153: Failed to process phase INSTALL of deployment "singleton.war" at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:154) at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1948) at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1881) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.NoClassDefFoundError: org/wildfly/clustering/service/Builder at org.jboss.as.test.clustering.cluster.singleton.service.AbstractServiceActivator.install(AbstractServiceActivator.java:59) at org.jboss.as.test.clustering.cluster.singleton.service.MyServiceActivator.activate(MyServiceActivator.java:38) at org.jboss.as.server.deployment.service.ServiceActivatorProcessor.deploy(ServiceActivatorProcessor.java:74) at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:147) ... 5 more Caused by: java.lang.ClassNotFoundException: org.wildfly.clustering.service.Builder from [Module "deployment.singleton.war:main" from Service Module Loader] at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:198) at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:363) at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:351) at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:93) ... 9 more {noformat} -- This message was sent by Atlassian JIRA (v6.4.11#64026)