Shamal Karunarathne [https://community.jboss.org/people/shamalk] created the discussion "[jbpm-console][Error] result returns more than one elements" To view the discussion, visit: https://community.jboss.org/message/745345#745345 -------------------------------------------------------------- Hi, I'm getting an error  when I try to start a process in JBPM-Console. This usually happens after a jboss restart or a system restart (not everytime). The only way I can fix this is by dropping the databases (jbpm5, task) and recreating them. Note: I'm using mysql as my database. I have attached my standalone.xml and the persistence.xml (~/Desktop/jbpm-installer/jboss-as-7.0.2.Final/standalone/deployments/jbpm-gwt-console-server.war/WEB-INF/classes/META-INF/persistence.xml) with this. Could you help me to resolve this problem? 13:43:35,006 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[default-host].[/gwt-console-server].[Resteasy]] (http-localhost-127.0.0.1-8080-5) Servlet.service() for servlet Resteasy threw exception: org.jboss.resteasy.spi.UnhandledException: javax.persistence.NonUniqueResultException: result returns more than one elements           at org.jboss.resteasy.core.SynchronousDispatcher.unwrapException(SynchronousDispatcher.java:345) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.core.SynchronousDispatcher.handleApplicationException(SynchronousDispatcher.java:321) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.core.SynchronousDispatcher.handleException(SynchronousDispatcher.java:214) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.core.SynchronousDispatcher.handleInvokerException(SynchronousDispatcher.java:190) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.core.SynchronousDispatcher.getResponse(SynchronousDispatcher.java:534) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:496) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:119) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:208) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:55) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:50) [resteasy-jaxrs-2.2.1.GA.jar:]           at javax.servlet.http.HttpServlet.service(HttpServlet.java:847) [jboss-servlet-api_3.0_spec-1.0.0.Final.jar:1.0.0.Final]           at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.jboss.bpm.console.server.util.GWTJsonFilter.doFilter(GWTJsonFilter.java:59) [classes:]           at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:139) [jboss-as-web-7.0.2.Final.jar:7.0.2.Final]           at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:480) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.jboss.as.web.NamingValve.invoke(NamingValve.java:57) [jboss-as-web-7.0.2.Final.jar:7.0.2.Final]           at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:154) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:362) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:667) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:952) [jbossweb-7.0.1.Final.jar:7.0.2.Final]           at java.lang.Thread.run(Thread.java:680) [:1.6.0_33] Caused by: javax.persistence.NonUniqueResultException: result returns more than one elements           at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:109) [hibernate-entitymanager-3.4.0.GA.jar:]           at org.jbpm.process.audit.JPAProcessInstanceDbLog.findProcessInstance(JPAProcessInstanceDbLog.java:124) [jbpm-bam-5.3.0.Final.jar:]           at org.jbpm.integration.console.CommandDelegate.startProcess(CommandDelegate.java:121) [jbpm-gwt-core-5.3.0.Final.jar:]           at org.jbpm.integration.console.ProcessManagement.newInstance(ProcessManagement.java:88) [jbpm-gwt-core-5.3.0.Final.jar:]           at org.jboss.bpm.console.server.FormProcessingFacade.startProcessWithUI(FormProcessingFacade.java:197) [classes:]           at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [:1.6.0_33]           at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [:1.6.0_33]           at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [:1.6.0_33]           at java.lang.reflect.Method.invoke(Method.java:597) [:1.6.0_33]           at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:140) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.core.ResourceMethod.invokeOnTarget(ResourceMethod.java:255) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.core.ResourceMethod.invoke(ResourceMethod.java:220) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.core.ResourceMethod.invoke(ResourceMethod.java:209) [resteasy-jaxrs-2.2.1.GA.jar:]           at org.jboss.resteasy.core.SynchronousDispatcher.getResponse(SynchronousDispatcher.java:519) [resteasy-jaxrs-2.2.1.GA.jar:]           ... 24 more 13:43:59,645 WARN  [org.jboss.seam.transaction.TransactionServletListener] (http-localhost-127.0.0.1-8080-5) Transaction was already started before the listener -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/745345#745345] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]