As of Log4j 3.0.0, common code for layouts based on Jackson have moved from the existing module logj-core to the new modules log4j-layout-jackson.
This module was introduced in Log4j 2.11.0 and requires Jackson.
Some features may require optional dependencies. These dependencies are specified in the documentation for those features.
Some Log4j features require external dependencies. See the Dependency Tree for the exact list of JAR files needed for these features.