After upgrading from 6.1.4 to 6.1.5 many of our tests fail with the following ClassCastException:
java.lang.ClassCastException: class org.hibernate.sql.results.graph.embeddable.internal.EmbeddableFetchInitializer cannot be cast to class org.hibernate.sql.results.graph.entity.AbstractEntityInitializer (org.hibernate.sql.results.graph.embeddable.internal.EmbeddableFetchInitializer and org.hibernate.sql.results.graph.entity.AbstractEntityInitializer are in unnamed module of loader 'app')
at org.hibernate.sql.results.graph.entity.internal.BatchEntitySelectFetchInitializer.endLoading(BatchEntitySelectFetchInitializer.java:225)
at org.hibernate.sql.results.internal.StandardRowReader.finishUp(StandardRowReader.java:161)
at org.hibernate.sql.results.spi.ListResultsConsumer.consume(ListResultsConsumer.java:168)
at org.hibernate.sql.results.spi.ListResultsConsumer.consume(ListResultsConsumer.java:32)
at org.hibernate.sql.exec.internal.JdbcSelectExecutorStandardImpl.doExecuteQuery(JdbcSelectExecutorStandardImpl.java:443)
at org.hibernate.sql.exec.internal.JdbcSelectExecutorStandardImpl.executeQuery(JdbcSelectExecutorStandardImpl.java:166)
at org.hibernate.sql.exec.internal.JdbcSelectExecutorStandardImpl.list(JdbcSelectExecutorStandardImpl.java:91)
at org.hibernate.sql.exec.spi.JdbcSelectExecutor.list(JdbcSelectExecutor.java:31)
at org.hibernate.query.sqm.internal.ConcreteSqmSelectQueryPlan.lambda$new$0(ConcreteSqmSelectQueryPlan.java:102)
at org.hibernate.query.sqm.internal.ConcreteSqmSelectQueryPlan.withCacheableSqmInterpretation(ConcreteSqmSelectQueryPlan.java:305)
at org.hibernate.query.sqm.internal.ConcreteSqmSelectQueryPlan.performList(ConcreteSqmSelectQueryPlan.java:246)
at org.hibernate.query.sqm.internal.QuerySqmImpl.doList(QuerySqmImpl.java:546)
at org.hibernate.query.spi.AbstractSelectionQuery.list(AbstractSelectionQuery.java:363)
at org.hibernate.query.sqm.internal.QuerySqmImpl.list(QuerySqmImpl.java:1032)
I can try to create a reproducer in the next days, but I think the stracktrace should provide enough information about the problem.