While migrating to Wildfly 27 (Java 11) I see a very similar exception:

16:26:45,480 ERROR [org.jboss.msc.service.fail]{} MSC000001: Failed to start service jboss.persistenceunit."xxx": org.jboss.msc.service.StartException in service jboss.persistenceunit."xxx": org.hibernate.resource.beans.container.internal.NotYetReadyException: CDI BeanManager not (yet) ready to use
{{ at org.jboss.as.jpa@27.0.0.Final//org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1$1.run(PersistenceUnitServiceImpl.java:199)}}
{{ at org.jboss.as.jpa@27.0.0.Final//org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1$1.run(PersistenceUnitServiceImpl.java:129)}}
{{ at java.base/java.security.AccessController.doPrivileged(Native Method)}}
{{ at org.wildfly.security.elytron-base@2.0.0.Final//org.wildfly.security.manager.WildFlySecurityManager.doChecked(WildFlySecurityManager.java:664)}}
{{ at org.jboss.as.jpa@27.0.0.Final//org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1.run(PersistenceUnitServiceImpl.java:214)}}
{{ at org.jboss.threads@2.4.0.Final//org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)}}
{{ at org.jboss.threads@2.4.0.Final//org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1990)}}
{{ at org.jboss.threads@2.4.0.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1486)}}
{{ at org.jboss.threads@2.4.0.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1377)}}
{{ at java.base/java.lang.Thread.run(Thread.java:829)}}
{{ at org.jboss.threads@2.4.0.Final//org.jboss.threads.JBossThread.run(JBossThread.java:513)}}
Caused by: org.hibernate.resource.beans.container.internal.NotYetReadyException: CDI BeanManager not (yet) ready to use
{{ at org.hibernate@6.1.5.Final//org.hibernate.resource.beans.container.internal.JpaCompliantLifecycleStrategy$NamedBeanImpl.initialize(JpaCompliantLifecycleStrategy.java:231)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.resource.beans.container.internal.CdiBeanContainerExtendedAccessImpl$NamedBeanImpl.initialize(CdiBeanContainerExtendedAccessImpl.java:165)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.resource.beans.container.internal.CdiBeanContainerExtendedAccessImpl$NamedBeanImpl.getBeanInstance(CdiBeanContainerExtendedAccessImpl.java:172)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.resource.beans.internal.ManagedBeanRegistryImpl$ContainedBeanManagedBeanAdapter.getBeanInstance(ManagedBeanRegistryImpl.java:155)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.mapping.BasicValue.setExplicitCustomType(BasicValue.java:828)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.cfg.annotations.BasicValueBinder.fillSimpleValue(BasicValueBinder.java:1238)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.cfg.SetBasicValueTypeSecondPass.doSecondPass(SetBasicValueTypeSecondPass.java:26)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1782)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1729)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:300)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1350)}}
{{ at org.hibernate@6.1.5.Final//org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1421)}}
{{ at org.hibernate.jipijapa-hibernate6@27.0.0.Final//org.jboss.as.jpa.hibernate.TwoPhaseBootstrapImpl.build(TwoPhaseBootstrapImpl.java:45)}}
{{ at org.jboss.as.jpa@27.0.0.Final//org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1$1.run(PersistenceUnitServiceImpl.java:171)}}
{{ ... 10 more}}
Caused by: java.lang.NullPointerException
{{ at org.hibernate@6.1.5.Final//org.hibernate.resource.beans.container.internal.JpaCompliantLifecycleStrategy$NamedBeanImpl.initialize(JpaCompliantLifecycleStrategy.java:228)}}

Debugging at JpaCompliantLifecycleStrategy.java:228 shows that a custom type implementing org.hibernate.usertype.UserType is being initialized. The BeanContainer in CdiBeanContainerExtendedAccessImpl.java:165 is the DUMMY_BEAN_CONTAINER, it’s usableBeanManager is null causes the NPE.

I’d be glad to help with testing/diagnosis, as this is currently a blocker for our migration.

Thanks,
Christian