Exceções são lançadas após adicionar as categorias

Após eu ter adicionado essas categorias, começou a lançar as seguintes exceções:

Exception in thread "main" java.lang.IllegalArgumentException: org.hibernate.QueryException: could not resolve property: itens of: br.com.byteshop.modelo.Pedido [SELECT produto.nome, SUM(item.quantidade), MAX(pedido.dataDoPedido) FROM br.com.byteshop.modelo.Pedido pedido JOIN pedido.itens item JOIN item.produto produto GROUP BY produto.nome ORDER BY item.quantidade DESC]
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:138)
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:181)
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:188)
    at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:725)
    at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:816)
    at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:23)
    at br.com.alura.loja.dao.PedidoDAO.relatorioDeVendas(PedidoDAO.java:56)
    at br.com.byteshop.testes.CadastroDePedido.main(CadastroDePedido.java:53)

Caused by: org.hibernate.QueryException: could not resolve property: itens of: br.com.byteshop.modelo.Pedido [SELECT produto.nome, SUM(item.quantidade), MAX(pedido.dataDoPedido) FROM br.com.byteshop.modelo.Pedido pedido JOIN pedido.itens item JOIN item.produto produto GROUP BY produto.nome ORDER BY item.quantidade DESC]
    at org.hibernate.QueryException.generateQueryException(QueryException.java:120)
    at org.hibernate.QueryException.wrapWithQueryString(QueryException.java:103)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:220)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:144)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:113)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:73)
    at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:162)
    at org.hibernate.internal.AbstractSharedSessionContract.getQueryPlan(AbstractSharedSessionContract.java:604)
    at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:716)
    ... 4 more

Caused by: org.hibernate.QueryException: could not resolve property: itens of: br.com.byteshop.modelo.Pedido
    at org.hibernate.persister.entity.AbstractPropertyMapping.propertyException(AbstractPropertyMapping.java:77)
    at org.hibernate.persister.entity.AbstractPropertyMapping.toType(AbstractPropertyMapping.java:71)
    at org.hibernate.persister.entity.AbstractEntityPersister.toType(AbstractEntityPersister.java:2043)
    at org.hibernate.hql.internal.ast.tree.FromElementType.getPropertyType(FromElementType.java:412)
    at org.hibernate.hql.internal.ast.tree.FromElement.getPropertyType(FromElement.java:520)
    at org.hibernate.hql.internal.ast.tree.DotNode.getDataType(DotNode.java:694)
    at org.hibernate.hql.internal.ast.tree.DotNode.prepareLhs(DotNode.java:269)
    at org.hibernate.hql.internal.ast.tree.DotNode.resolve(DotNode.java:209)
    at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:114)
    at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:109)
    at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromJoinElement(HqlSqlWalker.java:410)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.joinElement(HqlSqlBaseWalker.java:3983)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3769)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3647)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:732)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:588)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:325)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:273)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:276)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:192)
    ... 10 more