java/nio/channels/DatagramChannel/AdaptorMulticasting.java failed intermittently

----------System.out:(4/258)----------
Test family=INET, multicast group=/225.4.5.6, interface=ens3
Test family=UNSPEC, multicast group=/225.4.5.6, interface=ens3
Test family=INET6, multicast group=/225.4.5.6, interface=ens3
Test family=UNSPEC, multicast group=/ff02:0:0:0:0:0:0:a, interface=ens3
----------System.err:(16/962)----------
java.lang.RuntimeException
at AdaptorMulticasting.assertTrue(AdaptorMulticasting.java:448)
at AdaptorMulticasting.testSendNoReceive(AdaptorMulticasting.java:442)
at AdaptorMulticasting.testJoinGroup2(AdaptorMulticasting.java:229)
at AdaptorMulticasting.test(AdaptorMulticasting.java:97)
at AdaptorMulticasting.main(AdaptorMulticasting.java:79)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:298)
at java.base/java.lang.Thread.run(Thread.java:832)

JavaTest Message: Test threw exception: java.lang.RuntimeException
JavaTest Message: shutting down test

result: Failed. Execution failed: `main' threw exception: java.lang.RuntimeException