While starting a process instance through Business Central Console throws "result returns more than one elements" exception

Issue

• While starting a process instance through Business Central Console, it throws the following exception. What does it mean and how to fix this issue?

WARN  [org.jboss.resteasy.core.SynchronousDispatcher] (http-127.0.0.1-8080-3) failed to execute
javax.ws.rs.WebApplicationException: javax.persistence.NonUniqueResultException: result returns more than one elements
    at org.jboss.bpm.console.server.ProcessMgmtFacade.newInstance(ProcessMgmtFacade.java:214)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:140)
    ...
Caused by: javax.persistence.NonUniqueResultException: result returns more than one elements
    at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:137)
    at org.jbpm.process.audit.JPAProcessInstanceDbLog.findProcessInstance(JPAProcessInstanceDbLog.java:115)
    at org.jbpm.integration.console.CommandDelegate.startProcess(CommandDelegate.java:121)
    at org.jbpm.integration.console.ProcessManagement.newInstance(ProcessManagement.java:82)
    at org.jboss.bpm.console.server.ProcessMgmtFacade.newInstance(ProcessMgmtFacade.java:209)
    ... 41 more