ERROR - Unable to find job 'a3bb3a0d-aca3-40f5-8ff9-9400b563f369' on node 'SRDG3606:8815' (Job is ever started: true).
jvm 1 | 2020-02-26 16:06:02,894 INFO - Taking repository snapshots...
jvm 1 | 2020-02-26 16:06:02,901 INFO - Taking snapshot of repository 'GITHUB'...
jvm 1 | 2020-02-26 16:06:02,901 INFO - Determining head revision for repository: GITHUB
jvm 1 | 2020-02-26 16:06:02,906 ERROR - Error notifying task node of job finishing (job class: 6bb7f9b8-1179-4cc7-94ba-5e70a6411528, job id: com.pmease.quickbuild.CheckConditionJob, task node: SRDG3501:8810)
jvm 1 | org.hibernate.type.SerializationException: could not serialize
jvm 1 | at org.hibernate.internal.util.SerializationHelper.serialize(SerializationHelper.java:142)
jvm 1 | at org.hibernate.internal.util.SerializationHelper.serialize(SerializationHelper.java:167)
jvm 1 | at com.pmease.quickbuild.grid.GridJob.run(GridJob.java:150)
jvm 1 | at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
jvm 1 | at java.util.concurrent.FutureTask.run(FutureTask.java:266)
jvm 1 | at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
jvm 1 | at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
jvm 1 | at java.lang.Thread.run(Thread.java:748)
jvm 1 | Caused by: java.io.NotSerializableException: Not serializable.
jvm 1 | at java.util.InvalidPropertiesFormatException.writeObject(InvalidPropertiesFormatException.java:80)
jvm 1 | at sun.reflect.GeneratedMethodAccessor124.invoke(Unknown Source)
jvm 1 | at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
jvm 1 | at java.lang.reflect.Method.invoke(Method.java:498)
jvm 1 | at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
jvm 1 | at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
jvm 1 | at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
jvm 1 | at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
jvm 1 | at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
jvm 1 | at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
jvm 1 | at java.lang.Throwable.writeObject(Throwable.java:985)
jvm 1 | at sun.reflect.GeneratedMethodAccessor81.invoke(Unknown Source)
jvm 1 | at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
jvm 1 | at java.lang.reflect.Method.invoke(Method.java:498)
jvm 1 | at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
jvm 1 | at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
jvm 1 | at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
jvm 1 | at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
jvm 1 | at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
jvm 1 | at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
jvm 1 | at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
jvm 1 | at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
jvm 1 | at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
jvm 1 | at org.hibernate.internal.util.SerializationHelper.serialize(SerializationHelper.java:138)
jvm 1 | ... 7 more

Errors are occurring only on certain ports in the agent.
(The setting values for the ports is the same)
Do you happen to know what caused it?