# Regression of @MapsId in hibernate 5.4?

**URL:** <https://discourse.hibernate.org/t/regression-of-mapsid-in-hibernate-5-4/2785>\
**Category:** Hibernate ORM\
**Created:** [June 3, 2019, 12:22pm UTC](https://discourse.hibernate.org/t/regression-of-mapsid-in-hibernate-5-4/2785 "2019-06-03T12:22:16Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Polve](https://avatars.discourse-cdn.com/v4/letter/p/779978/32.png) [@Polve](https://discourse.hibernate.org/u/Polve)\
**Post date:** [June 3, 2019, 12:22pm UTC](https://discourse.hibernate.org/t/regression-of-mapsid-in-hibernate-5-4/2785/1 "2019-06-03T12:22:16Z")

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Hi everybody,  
I’m trying to upgrade Spring Boot of my project and the latest (development) builds are using Hibernate 5.4 but my project does not work anymore because a class using @MapsId is now unable to populate its id.

The error I get while trying to save a new object is:  
Caused by: org.hibernate.id.IdentifierGenerationException: null id generated for:class

Has anybody noticed the problem?

Is there a workaround, otherwise the problem is blocking my upgrade.

Thanks for any hints