TESTNG ConcurrentModificationException while running with #Test invocation count greater than 1 - unit-testing

Question

I am experiencing the following issue while running my tests. However, it only happens when I am using #DataProvider with a #Test that has invocation count greater than 1. I am not sure if the following link below is the same issue, because if I read correctly this issue has already been fixed in higher versions of the Eclipse TESTNG plugin 6.9.13.X (using this 6.9.14.201610261028).
TestNG Reporter org.testng.reporters.JUnitReportReporter#7a79be86 failed java.util.ConcurrentModificationException
Here is a simple code that is encountering the same problem:
#Test(dataProvider = "data", timeOut = 6000, threadPoolSize = 10, invocationCount = 5)
public final void x(String a,
String b, String c, String d,
String e, String f, String g){
System.out.println("D"
+ " - "
+ java.lang.Thread.currentThread().getId()
+ " - "
+ new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS")
.format(new Date()));
}
Here is a sample output:
Thread - 1274 - 2016-10-28 08:47:23.889 PASSED: x("00336293615",
"02/24/2016", "03/10/2016", "3", "0", "3", "11.57")
Thread - 1275 - 2016-10-28 08:47:23.897
Thread - 1273 - 2016-10-28 08:47:23.898
java.util.ConcurrentModificationException at
java.util.ArrayList$Itr.checkForComodification(Unknown Source) at
java.util.ArrayList$Itr.next(Unknown Source) at
org.testng.reporters.TextReporter.logResults(TextReporter.java:80) at
org.testng.reporters.TextReporter.onFinish(TextReporter.java:32) at
org.testng.TestRunner.fireEvent(TestRunner.java:1239) at
org.testng.TestRunner.afterRun(TestRunner.java:1030) at
org.testng.TestRunner.run(TestRunner.java:636) at
org.testng.SuiteRunner.runTest(SuiteRunner.java:366) at
org.testng.SuiteRunner.runSequentially(SuiteRunner.java:361) at
org.testng.SuiteRunner.privateRun(SuiteRunner.java:319) at
org.testng.SuiteRunner.run(SuiteRunner.java:268) at
org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52) at
org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86) at
org.testng.TestNG.runSuitesSequentially(TestNG.java:1244) at
org.testng.TestNG.runSuitesLocally(TestNG.java:1169) at
org.testng.TestNG.run(TestNG.java:1064) at
org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:132)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:236)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:81)
Sometimes it will also throw the following exceprions:
java.lang.NullPointerException at java.io.Writer.(Unknown
Source) at java.io.OutputStreamWriter.(Unknown Source) at
org.testng.remote.strprotocol.JsonMessageSender.sendMessage(JsonMessageSender.java:37)
at
org.testng.remote.strprotocol.MessageHub.sendMessage(MessageHub.java:43)
at
org.testng.remote.strprotocol.RemoteTestListener1.onTestSuccess(RemoteTestListener1.java:88)
at org.testng.internal.Invoker.runTestListeners(Invoker.java:1695)
at org.testng.internal.Invoker.runTestListeners(Invoker.java:1675)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:700) at
org.testng.internal.Invoker.invokeTestMethod(Invoker.java:820) at
org.testng.internal.TestMethodWithDataProviderMethodWorker.call(TestMethodWithDataProviderMethodWorker.java:75)
at
org.testng.internal.TestMethodWithDataProviderMethodWorker.call(TestMethodWithDataProviderMethodWorker.java:14)
at java.util.concurrent.FutureTask.run(Unknown Source) at
java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source) at
java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at
java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at
java.lang.Thread.run(Unknown Source) java.lang.IllegalStateException:
Trying to send a message on a shutdown sender at
org.testng.remote.strprotocol.JsonMessageSender.sendMessage(JsonMessageSender.java:31)
at
org.testng.remote.strprotocol.MessageHub.sendMessage(MessageHub.java:43)
at
org.testng.remote.strprotocol.RemoteTestListener1.onTestStart(RemoteTestListener1.java:49)
at org.testng.internal.Invoker.runTestListeners(Invoker.java:1700)
at org.testng.internal.Invoker.runTestListeners(Invoker.java:1675)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:619) at
org.testng.internal.Invoker.invokeTestMethod(Invoker.java:820) at
org.testng.internal.TestMethodWithDataProviderMethodWorker.call(TestMethodWithDataProviderMethodWorker.java:75)
at
org.testng.internal.TestMethodWithDataProviderMethodWorker.call(TestMethodWithDataProviderMethodWorker.java:14)
at java.util.concurrent.FutureTask.run(Unknown Source) at
java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source) at
java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at
java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at
java.lang.Thread.run(Unknown Source)
Please tell me if you guys need more information.
Thanks!!!