"java.io.NotSerializableException: org.hibernate.util.MarkerObject" in Spring/Hibernate

Issue

Encountering an exception related to org.hibernate.util.MarkerObject when using Spring Web Flow

org.springframework.webflow.execution.repository.snapshot.SnapshotCreationException: Could not serialize flow execution; make sure all objects stored in flow or flash scope are serializable
        at org.springframework.webflow.execution.repository.snapshot.SerializedFlowExecutionSnapshot.<init>(SerializedFlowExecutionSnapshot.java:74)
        at org.springframework.webflow.execution.repository.snapshot.SerializedFlowExecutionSnapshotFactory.createSnapshot(SerializedFlowExecutionSnapshotFactory.java:70)
        ...
Caused by: java.io.NotSerializableException: org.hibernate.util.MarkerObject
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1183)
        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:347)
        at org.hibernate.engine.StatefulPersistenceContext.serialize(StatefulPersistenceContext.java:1426)
        at org.hibernate.impl.SessionImpl.writeObject(SessionImpl.java:2018)
        ...
        at org.springframework.webflow.execution.repository.snapshot.SerializedFlowExecutionSnapshot.<init>(SerializedFlowExecutionSnapshot.java:69)