Hopefully this will stop someone from wasting a day of their life… If you pass in the following when you start your Java application: java -Dlog4j.configuration=file:///some/path/log4j.properties And that file contains a class that is not on the class path log4j.appender.myAppender=biz.minaret.log4j.DatedFileAppender log4j.rootLogger=error, myAppender Then due to the log4j static initialisers you will not see an error […]