ILockSearchCriteria findlocks throws exception

I am unable to figure out the cause for findLocks throwing exception.
I am trying to find locks on files (same files) in both, my workspace and the stream my workspace flows with.
When I pass the stream to getStreams and I run this code:
ILockSearchCriteria criteria = ILockSearchCriteria.FACTORY.newInstance();
criteria.getVersionables().addAll(versionableHandles);
criteria.getComponents().addAll(compHandles);
criteria.getStreams().add(streamHandle);
ILockSearchResult result = workspaceManager.findLocks(criteria, IWorkspaceManager.MAX_QUERY_SIZE, getProgressMonitor());
List<IStreamLockReport> report = (List<IStreamLockReport>) result.getReports();
log("The size should not be more than 1, since we are only looking at one stream: " + report.size());

The report.size() returns 0.

The second time I run the same exact code, except I change what I pass to getStreams(), which is this:

IWorkspaceHandle wsh = (IWorkspaceHandle) IWorkspace.ITEM_TYPE.createItemHandle(UUID.valueOf(workspaceUUID), null);
criteria2.getStreams().add(wsh);

And for criteria2, which has same inputs except for the above, I get an exception.
Here is the excerpt from the long exception list:

com.ibm.team.repository.common.TeamRepositoryException: Internal error
[04-Apr-15 09:42:23:847 BST] 00000019 [revertChangesets]     at com.ibm.team.scm.service.internal.query.ScmQueryService.findLocks(ScmQueryService.java:2172)
[04-Apr-15 09:42:23:847 BST] 00000019 [revertChangesets]     at sun.reflect.GeneratedMethodAccessor510.invoke(null)
[04-Apr-15 09:42:23:847 BST] 00000019 [revertChangesets]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
[04-Apr-15 09:42:23:847 BST] 00000019 [revertChangesets]     at java.lang.reflect.Method.invoke(Method.java:611)
[04-Apr-15 09:42:23:848 BST] 00000019 [revertChangesets]     at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)
[04-Apr-15 09:42:23:848 BST] 00000019 [revertChangesets]     at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)
[04-Apr-15 09:42:23:848 BST] 00000019 [revertChangesets]     at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
[04-Apr-15 09:42:23:848 BST] 00000019 [revertChangesets]     at com.sun.proxy.$Proxy1521.findLocks(null)
[04-Apr-15 09:42:23:848 BST] 00000019 [revertChangesets]     at sun.reflect.GeneratedMethodAccessor510.invoke(null)
...
...
...
04-Apr-15 09:42:23:859 BST] 00000019 [revertChangesets]     at com.ibm.team.scm.client.internal.ScmServiceInterfaceProxy.invoke(ScmServiceInterfaceProxy.java:92)
[04-Apr-15 09:42:23:859 BST] 00000019 [revertChangesets]     at com.sun.proxy.$Proxy36.findLocks(Unknown Source)
[04-Apr-15 09:42:23:859 BST] 00000019 [revertChangesets]     at com.ibm.team.scm.client.internal.WorkspaceManager.findLocks(WorkspaceManager.java:2759)
[04-Apr-15 09:42:23:859 BST] 00000019 [revertChangesets]     at com.ibm.aries.buildtasks.rtc.RevertChangesets.testRevertChangeSetsForPB(RevertChangesets.java:376)
[04-Apr-15 09:42:23:860 BST] 00000019 [revertChangesets]     at com.ibm.aries.buildtasks.rtc.RevertChangesets.doExecute(RevertChangesets.java:199)
[04-Apr-15 09:42:23:860 BST] 00000019 [revertChangesets]     at com.ibm.team.build.ant.task.AbstractTeamBuildTask.execute(AbstractTeamBuildTask.java:666)
[04-Apr-15 09:42:23:860 BST] 00000019 [revertChangesets]     at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)


I need help figuring this out. What is the cause of this exception?
Thanks much.