Has anyone encountered an issue with SLA agent throwing ConcurrentModificationException though the workitem is not being accessed by anyone else??

System Info : CPM 7.1.3 on Pega 7.1.8

2016-04-19 14:25:14,414 [   PegaRULES-Batch-4] [  STANDARD] [                    ] [        CCI:01.01.01] (      internal.mgmt.Executable) ERROR   - Exception

java.util.ConcurrentModificationException

at java.util.HashMap$HashIterator.nextEntry(HashMap.java:922)

at java.util.HashMap$ValueIterator.next(HashMap.java:950)

at com.pega.pegarules.data.internal.clipboard.ClipboardPageImpl.clearMessages(ClipboardPageImpl.java:3869)

at com.pegarules.generated.activity.ra_action_closeinteration_af6cf4aa5e5116d8f7b1be514bbe101d.step2_circum0(ra_action_closeinteration_af6cf4aa5e5116d8f7b1be514bbe101d.java:285)

at com.pegarules.generated.activity.ra_action_closeinteration_af6cf4aa5e5116d8f7b1be514bbe101d.perform(ra_action_closeinteration_af6cf4aa5e5116d8f7b1be514bbe101d.java:86)

at com.pega.pegarules.session.internal.mgmt.Executable.doActivity(Executable.java:3500)

at com.pegarules.generated.callActivity_071017_xvj4o_pyNDBZ4Gy293rekg.callActivity07_10_17(callActivity_071017_xvj4o_pyNDBZ4Gy293rekg.java:122)

at com.pegarules.generated.callActivity_071017_xvj4o_pyNDBZ4Gy293rekg.invoke(callActivity_071017_xvj4o_pyNDBZ4Gy293rekg.java:82)

at com.pega.pegarules.generation.internal.library.LibraryRuntime.resolveAndinvokeFunctionViaReflection(LibraryRuntime.java:133)

at com.pega.pegarules.generation.internal.library.LibraryRuntime.invokeLibraryRuntime(LibraryRuntime.java:110)

at com.pega.pegarules.session.internal.mgmt.Executable.invokeLibraryRuntime(Executable.java:8954)

at com.pega.pegarules.priv.generator.LibrarySupport.resolveAndInvokeFunctionViaReflection(LibrarySupport.java:181)

at com.pegarules.generated.pega_rules_utilities.callActivity(pega_rules_utilities.java:1619)

at com.pegarules.generated.activity.ra_action_executesla_385b3e0f8d36abe26bfa86b4b22f803a.step19_circum0(ra_action_executesla_385b3e0f8d36abe26bfa86b4b22f803a.java:2107)

at com.pegarules.generated.activity.ra_action_executesla_385b3e0f8d36abe26bfa86b4b22f803a.perform(ra_action_executesla_385b3e0f8d36abe26bfa86b4b22f803a.java:434)

at com.pega.pegarules.session.internal.mgmt.Executable.doActivity(Executable.java:3500)

at com.pega.pegarules.session.internal.mgmt.Executable.invokeActivity(Executable.java:10521)

at com.pegarules.generated.activity.ra_action_processevent_b20b900d4f9f22f92e8fd368c9027da2.step7_circum0(ra_action_processevent_b20b900d4f9f22f92e8fd368c9027da2.java:735)

at com.pegarules.generated.activity.ra_action_processevent_b20b900d4f9f22f92e8fd368c9027da2.perform(ra_action_processevent_b20b900d4f9f22f92e8fd368c9027da2.java:198)

at com.pega.pegarules.session.internal.mgmt.Executable.doActivity(Executable.java:3500)

at com.pega.pegarules.session.internal.async.agent.QueueProcessor.runActivity(QueueProcessor.java:721)

at com.pega.pegarules.session.internal.async.agent.QueueProcessor.execute(QueueProcessor.java:602)

at com.pega.pegarules.session.internal.async.BatchRequestorTask.run(BatchRequestorTask.java:945)

at com.pega.pegarules.session.internal.PRSessionProviderImpl.performTargetActionWithLock(PRSessionProviderImpl.java:1259)

at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:1008)

at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:901)

at com.pega.pegarules.session.internal.async.BatchRequestorTask.run(BatchRequestorTask.java:670)

at com.pega.jsr166backport.java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:991)

at com.pega.jsr166backport.java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:532)

at java.lang.Thread.run(Thread.java:745)