[Occasional Exception] JGroups throws NPE into log

[0m[33m15:03:18,845 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,846 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,847 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,848 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,849 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,850 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,851 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,857 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,861 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-3,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,862 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,862 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-3,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,862 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-12,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,863 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-12,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,865 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-12,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,866 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-12,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,867 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-12,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,869 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-12,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,870 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-12,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,870 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-3,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,871 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-3,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,871 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-12,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,872 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,872 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-12,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,874 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,874 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-12,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[33m15:03:18,874 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-4,null,null) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[31m15:03:18,876 ERROR [stderr] (thread-4,null,null) Exception in thread "thread-4,null,null" java.lang.NullPointerException
[0m[33m15:03:18,876 WARN  [org.jgroups.protocols.ASYM_ENCRYPT] (thread-13,ee,hsc-1-8k27l) hsc-1-8k27l: unrecognized cipher; discarding message from hsc-1-rbb2h
[0m[31m15:03:18,876 ERROR [stderr] (thread-4,null,null) 	at org.jgroups@4.0.19.Final-redhat-00001//org.jgroups.protocols.Encrypt.up(Encrypt.java:192)
[0m[31m15:03:18,876 ERROR [stderr] (thread-4,null,null) 	at org.jgroups@4.0.19.Final-redhat-00001//org.jgroups.protocols.ASYM_ENCRYPT.up(ASYM_ENCRYPT.java:176)
[0m[31m15:03:18,876 ERROR [stderr] (thread-4,null,null) 	at org.jgroups@4.0.19.Final-redhat-00001//org.jgroups.stack.Protocol.up(Protocol.java:371)
[0m[31m15:03:18,877 ERROR [stderr] (thread-4,null,null) 	at org.jgroups@4.0.19.Final-redhat-00001//org.jgroups.protocols.FD_ALL.up(FD_ALL.java:216)
[0m[31m15:03:18,877 ERROR [stderr] (thread-4,null,null) 	at org.jgroups@4.0.19.Final-redhat-00001//org.jgroups.stack.Protocol.up(Protocol.java:371)
[0m[31m15:03:18,877 ERROR [stderr] (thread-4,null,null) 	at org.jgroups@4.0.19.Final-redhat-00001//org.jgroups.stack.Protocol.up(Protocol.java:371)
[0m[31m15:03:18,877 ERROR [stderr] (thread-4,null,null) 	at org.jgroups@4.0.19.Final-redhat-00001//org.jgroups.stack.Protocol.up(Protocol.java:371)
[0m[31m15:03:18,877 ERROR [stderr] (thread-4,null,null) 	at org.jgroups@4.0.19.Final-redhat-00001//org.jgroups.protocols.TP.passBatchUp(TP.java:1276)
[0m[31m15:03:18,877 ERROR [stderr] (thread-4,null,null) 	at org.jgroups@4.0.19.Final-redhat-00001//org.jgroups.util.SubmitToThreadPool$BatchHandler.passBatchUp(SubmitToThreadPool.java:140)
[0m[31m15:03:18,878 ERROR [stderr] (thread-4,null,null) 	at org.jgroups@4.0.19.Final-redhat-00001//org.jgroups.util.SubmitToThreadPool$BatchHandler.run(SubmitToThreadPool.java:136)
[0m[31m15:03:18,878 ERROR [stderr] (thread-4,null,null) 	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
[0m[31m15:03:18,878 ERROR [stderr] (thread-4,null,null) 	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
[0m[31m15:03:18,878 ERROR [stderr] (thread-4,null,null) 	at org.jboss.as.clustering.jgroups@7.2.2.GA-redhat-00001//org.jboss.as.clustering.jgroups.ClassLoaderThreadFactory.lambda$newThread$0(ClassLoaderThreadFactory.java:52)
[0m[31m15:03:18,878 ERROR [stderr] (thread-4,null,null) 	at java.base/java.lang.Thread.run(Thread.java:834)