Error running 'personal builds' using Jenkins pipeline with the team concert plugin

I have a Pipeline build that I want to execute as a personal build from RTC. This is working well for single builds but if I (or anyone else) try and execute a second one while a build is already running it fails.

Here is the exception:

RTC : checkout...
RTC : Build initiated by request from RTC

Substituted the following build property variables:
	team.scm.fetchDestination = /home/jenkins/RTC_EXTRACTS/${requestUUID}   -->   team.scm.fetchDestination = /home/jenkins/RTC_EXTRACTS/_E2kKgKjvEeaSpNHaJ5hK0A

RTC Checkout : Source control setup
FATAL: RTC : checkout failure: Unable to "start" build activity with label "Jazz Source Control setup" because the build with ID "_E2kxkKjvEeaSpNHaJ5hK0A", build definition ID "WorkspaceBuild", label "Hudson/Jenkins build not found!" is in the "COMPLETED" state.
com.ibm.team.build.common.TeamBuildStateException: Unable to "start" build activity with label "Jazz Source Control setup" because the build with ID "_E2kxkKjvEeaSpNHaJ5hK0A", build definition ID "WorkspaceBuild", label "Hudson/Jenkins build not found!" is in the "COMPLETED" state.
	at com.ibm.team.build.internal.service.TeamBuildService.createIllegalBuildStateForActivityException(TeamBuildService.java:1599)
	at com.ibm.team.build.internal.service.TeamBuildService$20.run(TeamBuildService.java:1331)
	at com.ibm.team.build.internal.service.AbstractTeamBuildService.runAsRetryable(AbstractTeamBuildService.java:435)
	at com.ibm.team.build.internal.service.AbstractTeamBuildService.runAsRetryableIncludingStaleData(AbstractTeamBuildService.java:393)
	at com.ibm.team.build.internal.service.TeamBuildService.startBuildActivityWithoutProcess(TeamBuildService.java:1321)
	at com.ibm.team.build.internal.service.TeamBuildService$21$1.run(TeamBuildService.java:1435)
	at com.ibm.team.process.internal.common.advice.runtime.OperationAdviceManager.runOperation(OperationAdviceManager.java:1393)
	at com.ibm.team.process.internal.common.advice.runtime.OperationAdviceManager.advise(OperationAdviceManager.java:326)
	at com.ibm.team.process.internal.common.util.AbstractProcess.doAdvise(AbstractProcess.java:197)
	at com.ibm.team.process.internal.service.ServerProcess.access$2(ServerProcess.java:1)
	at com.ibm.team.process.internal.service.ServerProcess$2.run(ServerProcess.java:159)
	at com.ibm.team.repository.service.internal.PrimitiveTransactionService$3.run(PrimitiveTransactionService.java:162)
	at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase$Transaction.run(RepositoryDatabase.java:567)
	at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase$2.run(RepositoryDatabase.java:351)
	at com.ibm.team.repository.service.internal.rdb.ConnectionPoolService.withCurrentConnection(ConnectionPoolService.java:472)
	at sun.reflect.GeneratedMethodAccessor79.invoke(null)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
	at java.lang.reflect.Method.invoke(Method.java:611)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
	at com.sun.proxy.$Proxy120.withCurrentConnection(null)
	at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase.runTransaction(RepositoryDatabase.java:348)
	at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase.runInTransaction(RepositoryDatabase.java:288)
	at com.ibm.team.repository.service.internal.PrimitiveTransactionService.runInTransaction(PrimitiveTransactionService.java:96)
	at com.ibm.team.repository.service.internal.PrimitiveTransactionService.runInTransaction(PrimitiveTransactionService.java:91)
	at sun.reflect.GeneratedMethodAccessor347.invoke(null)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
	at java.lang.reflect.Method.invoke(Method.java:611)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
	at com.sun.proxy.$Proxy160.runInTransaction(null)
	at com.ibm.team.repository.service.internal.TransactionService.runInTransaction(TransactionService.java:37)
	at sun.reflect.GeneratedMethodAccessor348.invoke(null)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
	at java.lang.reflect.Method.invoke(Method.java:611)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
	at com.sun.proxy.$Proxy246.runInTransaction(null)
	at com.ibm.team.process.internal.service.ProcessService.runInTransaction(ProcessService.java:4831)
	at com.ibm.team.process.internal.service.ProcessService.runInTransaction(ProcessService.java:4838)
	at com.ibm.team.process.internal.service.ServerProcess.adviseAndExecute(ServerProcess.java:156)
	at com.ibm.team.build.internal.service.TeamBuildService$21.run(TeamBuildService.java:1430)
	at com.ibm.team.build.internal.service.TeamBuildService$21.run(TeamBuildService.java:1)
	at com.ibm.team.build.internal.service.AbstractTeamBuildService.runWithItemLock(AbstractTeamBuildService.java:488)
	at com.ibm.team.build.internal.service.TeamBuildService.startBuildActivity(TeamBuildService.java:1428)
	at sun.reflect.GeneratedMethodAccessor1409.invoke(null)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
	at java.lang.reflect.Method.invoke(Method.java:611)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)
	at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
	at com.sun.proxy.$Proxy1073.startBuildActivity(null)
	at sun.reflect.GeneratedMethodAccessor1409.invoke(null)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
	at java.lang.reflect.Method.invoke(Method.java:611)
	at com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleMethod(AbstractTeamServerServlet.java:1457)
	at com.ibm.team.repository.servlet.AbstractTeamServerServlet.executeMethod(AbstractTeamServerServlet.java:1010)
	at com.ibm.team.repository.servlet.AbstractTeamServerServlet.doPost(AbstractTeamServerServlet.java:777)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
	at com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleRequest2(AbstractTeamServerServlet.java:2456)
	at com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleRequest(AbstractTeamServerServlet.java:2244)
	at com.ibm.team.repository.servlet.AbstractTeamServerServlet.access$0(AbstractTeamServerServlet.java:2229)
	at com.ibm.team.repository.servlet.AbstractTeamServerServlet$1.service(AbstractTeamServerServlet.java:241)
	at com.ibm.team.repository.internal.service.auth.impl.JAuthHandler$1.run(JAuthHandler.java:109)
	at com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleAuthentication(AbstractTeamServerServlet.java:1947)
	at com.ibm.team.repository.servlet.AbstractTeamServerServlet.service(AbstractTeamServerServlet.java:1735)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
	at org.eclipse.equinox.http.registry.internal.ServletManager$ServletWrapper.service(ServletManager.java:180)
	at org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61)
	at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:126)
	at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:76)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
	at org.eclipse.equinox.servletbridge.BridgeServlet.service(BridgeServlet.java:120)
	at com.ibm.team.repository.server.servletbridge.JazzServlet.service(JazzServlet.java:74)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at com.ibm.team.repository.server.servletbridge.BridgeFilter.processDelegate(BridgeFilter.java:165)
	at com.ibm.team.repository.server.servletbridge.BridgeFilter.doFilter(BridgeFilter.java:198)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:614)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
	at org.apache.catalina.authenticator.SingleSignOn.invoke(SingleSignOn.java:321)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:442)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1082)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:623)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:939)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:963)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:767)
	at com.ibm.team.repository.common.internal.marshal.util.MarshallerUtil.decodeExceptions(MarshallerUtil.java:364)
	at com.ibm.team.repository.common.internal.marshal.util.MarshallerUtil.decodeExceptions(MarshallerUtil.java:334)
	at com.ibm.team.repository.common.internal.marshal.util.MarshallerUtil.decodeFault(MarshallerUtil.java:299)
	at com.ibm.team.repository.transport.client.RemoteTeamService.constructExceptionFromFault(RemoteTeamService.java:621)
	at com.ibm.team.repository.transport.client.RemoteTeamService.executeMethod(RemoteTeamService.java:505)
	at com.ibm.team.repository.transport.client.RemoteTeamService.invoke(RemoteTeamService.java:194)
	at com.ibm.team.repository.transport.client.ServiceInvocationHandler.invoke(ServiceInvocationHandler.java:43)
	at com.sun.proxy.$Proxy83.startBuildActivity(Unknown Source)
	at sun.reflect.GeneratedMethodAccessor679.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.ibm.team.repository.client.internal.ServiceInterfaceProxy.invokeServiceCall(ServiceInterfaceProxy.java:254)
	at com.ibm.team.repository.client.internal.ServiceInterfaceProxy.invoke(ServiceInterfaceProxy.java:110)
	at com.sun.proxy.$Proxy83.startBuildActivity(Unknown Source)
	at com.ibm.team.build.internal.client.TeamBuildClient$1StartBuildActivityRunnable.run(TeamBuildClient.java:314)
	at com.ibm.team.process.internal.common.advice.runtime.OperationAdviceManager.runRunnable(OperationAdviceManager.java:1466)
	at com.ibm.team.process.internal.common.advice.runtime.OperationAdviceManager.execute(OperationAdviceManager.java:208)
	at com.ibm.team.process.internal.client.ProcessClientService.execute(ProcessClientService.java:773)
	at com.ibm.team.build.internal.client.TeamBuildClient$9.run(TeamBuildClient.java:328)
	at com.ibm.team.repository.client.internal.TeamRepository$3.run(TeamRepository.java:1324)
	at com.ibm.team.repository.common.transport.CancelableCaller.call(CancelableCaller.java:79)
	at com.ibm.team.repository.client.internal.TeamRepository.callCancelableService(TeamRepository.java:1319)
	at com.ibm.team.build.internal.client.AbstractTeamBuildClient.callCancelableService(AbstractTeamBuildClient.java:268)
	at com.ibm.team.build.internal.client.TeamBuildClient.startBuildActivity(TeamBuildClient.java:322)
	at com.ibm.team.build.internal.hjplugin.rtc.BuildConnection.startBuildActivity(BuildConnection.java:545)
	at com.ibm.team.build.internal.hjplugin.rtc.RepositoryConnection.accept(RepositoryConnection.java:447)
	at com.ibm.team.build.internal.hjplugin.rtc.RTCFacade.accept(RTCFacade.java:488)
	at sun.reflect.GeneratedMethodAccessor900.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.ibm.team.build.internal.hjplugin.RTCFacadeFactory$RTCFacadeWrapper.invoke(RTCFacadeFactory.java:127)
	at com.ibm.team.build.internal.hjplugin.RTCAcceptTask.invoke(RTCAcceptTask.java:203)
	at com.ibm.team.build.internal.hjplugin.RTCAcceptTask.invoke(RTCAcceptTask.java:34)
	at hudson.FilePath.act(FilePath.java:1018)
	at hudson.FilePath.act(FilePath.java:996)
	at com.ibm.team.build.internal.hjplugin.RTCScm.checkout(RTCScm.java:2159)
	at org.jenkinsci.plugins.workflow.steps.scm.SCMStep.checkout(SCMStep.java:109)
	at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:83)
	at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:73)
	at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1$1.call(AbstractSynchronousNonBlockingStepExecution.java:52)
	at hudson.security.ACL.impersonate(ACL.java:221)
	at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1.run(AbstractSynchronousNonBlockingStepExecution.java:49)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
FATAL: RTC : checkout failure: RTC : checkout failure: Unable to "start" build activity with label "Jazz Source Control setup" because the build with ID "_E2kxkKjvEeaSpNHaJ5hK0A", build definition ID "WorkspaceBuild", label "Hudson/Jenkins build not found!" is in the "COMPLETED" state.
hudson.AbortException: RTC : checkout failure: Unable to "start" build activity with label "Jazz Source Control setup" because the build with ID "_E2kxkKjvEeaSpNHaJ5hK0A", build definition ID "WorkspaceBuild", label "Hudson/Jenkins build not found!" is in the "COMPLETED" state.
	at com.ibm.team.build.internal.hjplugin.RTCAcceptTask.invoke(RTCAcceptTask.java:246)
	at com.ibm.team.build.internal.hjplugin.RTCAcceptTask.invoke(RTCAcceptTask.java:34)
	at hudson.FilePath.act(FilePath.java:1018)
	at hudson.FilePath.act(FilePath.java:996)
	at com.ibm.team.build.internal.hjplugin.RTCScm.checkout(RTCScm.java:2159)
	at org.jenkinsci.plugins.workflow.steps.scm.SCMStep.checkout(SCMStep.java:109)
	at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:83)
	at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:73)
	at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1$1.call(AbstractSynchronousNonBlockingStepExecution.java:52)
	at hudson.security.ACL.impersonate(ACL.java:221)
	at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1.run(AbstractSynchronousNonBlockingStepExecution.java:49)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	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)
[Pipeline] }

As soon as I start the build in RTC I can see that it will fail, instead of a build number in 'Label' column there is just the text 'Hudson/Jenkins build not found!' (Tried to upload a screen shot but it does not seem to be working).

This also happens when two different users request a build at the same time - so it's not restricted to a single user.

I'm using these levels:

Jenkins: 2.19.1
RTC: 5.0.2
Team Concert plugin: 1.2.0.1
Pipeline: 2.4

Any suggestions/workarounds?

Thanks, Zoe