Marius K ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=70121%3... ) *updated* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiZjg4NjYyOWEw... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16437?atlOrigin=eyJpIjoiZjg4Nj... ) HHH-16437 ( https://hibernate.atlassian.net/browse/HHH-16437?atlOrigin=eyJpIjoiZjg4Nj... ) class org.hibernate.mapping.BasicValue cannot be cast to class org.hibernate.mapping.ToOne ( https://hibernate.atlassian.net/browse/HHH-16437?atlOrigin=eyJpIjoiZjg4Nj... ) Change By: Marius K ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=70121%3... ) Hi, I have a One-To-Many relation with the Many-entity having an composite id with AttributeOverrides. This works fine with 6.2.0-CR3 ( and 5), but starts failing with CR4. {noformat}java.lang.ClassCastException: class org.hibernate.mapping.BasicValue cannot be cast to class org.hibernate.mapping.ToOne (org.hibernate.mapping.BasicValue and org.hibernate.mapping.ToOne are in unnamed module of loader 'app'){noformat} I attached a test case. [^hibernate-orm-6.zip] {noformat}@Entity public class Contract implements Serializable { private static final long serialVersionUID = 1L; @Id private Integer contractId; @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "id.contractId") @OrderBy(value = "id.positionNumber") private List<Contractposition> contractpositions = new ArrayList<>();{noformat} {noformat}@Entity public class Contractposition implements Serializable { private static final long serialVersionUID = 1L; @EmbeddedId @AttributeOverrides( { @AttributeOverride(name = "contractId", column = @Column(name = "VERTRAG_ID", nullable = false)), @AttributeOverride(name = "positionNumber", column = @Column(name = "POSITIONSNUMMER", nullable = false))}) private ContractpositionId id;{noformat} {noformat}@Embeddable public class ContractpositionId implements Serializable { private static final long serialVersionUID = 1L; @Column(name = "VERTRAG_ID", nullable = false) private Integer contractId; @Column(name = "POSITIONSNUMMER", nullable = false) private int positionNumber;{noformat} Debugging shows: !image-20230405-073033.png|width=869,height=476! ( https://hibernate.atlassian.net/browse/HHH-16437#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16437#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#100221- sha1:78e8bd6 )