Handlers can be created with the same name as an existing handler. This was done to reconfigure differences in the logging subsystem XML and the logging.properties file. The problem is it will replace a handler during an ADD operation if the same name is used on another parent resource.

/subsystem=logging/async-handler=CONSOLE:add(queue-length=10,overflow-action=BLOCK)

This will replace the default console handler with the new one keeping the existing console-handler resource. The next boot also fails with no indication on the console.