Comment From: lhotari
I'm adding a comment here just in case anyone else has issues with Spring Boot 2.3.3 and Jackson 2.11.2 . After upgrading a particular app to Spring Boot 2.3.3 Jackson serialization started failing for a particular case with "com.fasterxml.jackson.databind.JsonMappingException: Strange Map type java.util.Map: cannot determine type parameters". I have reported the issue as https://github.com/FasterXML/jackson-databind/issues/2821 .
Comment From: borgytan
after upgrading to Spring Boot 2.3.3 embedded tomcat refuses to start up with this error: Caused by: java.lang.NoClassDefFoundError: com/fasterxml/jackson/datatype/jdk8/Jdk8Deserializers
downgrading back to 2.3.2 and it runs again.
Comment From: snicoll
@borgytan a jar may have been corrupted when you downloaded it. Rather that downgrading Spring Boot, you could try to clean your cache or only downgrade Jackson to see if that fixes the issue. If not, please open a separate issue with a small sample that reproduces the problem you've described (attached as a zip to the issue or a link to a GitHub repository).
Comment From: borgytan
@snicoll thanks for your response. the jar that maven downloaded was indeed corrupted, so i downloaded a fixed copy and put that into my repository, all good now. thanks and apologies for the false alarm.