Andrea Boriero ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *updated* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiYzczZWM0Nzcz... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16322?atlOrigin=eyJpIjoiYzczZW... ) HHH-16322 ( https://hibernate.atlassian.net/browse/HHH-16322?atlOrigin=eyJpIjoiYzczZW... ) Merge of entities having a collection with orphanRemoval true fails when bytecode enhancement is enabled ( https://hibernate.atlassian.net/browse/HHH-16322?atlOrigin=eyJpIjoiYzczZW... ) Change By: Andrea Boriero ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) given {noformat}@Entity(name = "parent") @Table(name = "parent") public static class Parent { @Id private Long id; @OneToMany(mappedBy = "parent", cascade = { MERGE }, orphanRemoval = true, fetch = FetchType.LAZY) private List<Child> children = new ArrayList<>(); } @Entity @Table(name = "child") public static class Child { @Id private Long id; @ManyToOne(fetch = FetchType.LAZY) private Parent parent; }{noformat} the following {code:java}inTransaction( session -> { Parent parent = new Parent(); parent = session.merge( parent ); Child child = new Child(); child = session.merge( child ); parent.addChild( child ); } );{code} causes {code:java}org.hibernate.HibernateException: A collection with cascade="all-delete-orphan" was no longer referenced by the owning entity instance: Parent.children{code} ( https://hibernate.atlassian.net/browse/HHH-16322#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16322#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100217- sha1:d601792 )