Hi, I am using logback (latest version) on Tomcat, and have this error when trying to start the application: *Exception in thread "RMI RenewClean-<ip>:<port>" java.lang.ClassCircularityError: java/util/logging/LogRecord* *at org.slf4j.bridge.SLF4JBridgeHandler.getSLF4JLogger(SLF4JBridgeHandler.java:200) * *at org.slf4j.bridge.SLF4JBridgeHandler.publish(SLF4JBridgeHandler.java:289) * *at java.util.logging.Logger.log(Logger.java:458)* *at java.util.logging.Logger.doLog(Logger.java:480)* *at java.util.logging.Logger.logp(Logger.java:596)* The error is blocking Tomcat startup. The application has logback and jul-over-slf4j bridge JARs inside, and is using a servlet context listener to run * SLF4JBridgeHandler.removeHandlersForRootLogger()* and * SLF4JBridgeHandler.install()* on startup. The *logback.xml* used has * ch.qos.logback.classic.jul.LevelChangePropagator* context listener in it, with *resetJUL* set to *true*. I saw a thread on this mailing list in February 2011<http://mailman.qos.ch/pipermail/slf4j-user/2011-February/001044.html> with the similar issue so it might be quite old. Tomcat version is 7, but the mail list thread and this StackOverflow<http://stackoverflow.com/questions/2656565/classcircularityerror-when-running-tomcat6-from-eclipse>question are using Tomcat 6 and having the same problem. As the last answer on StackOverflow correctly says, error is reproducible only if the *LevelChangePropagator* element is in the beginning of * logback.xml*. Moving it to the end of the file fixes the issue, so it has an easy workaround. If you have problems reproducing it please let me know, I'll try to provide a test project. -- Best regards, Sergey Parhomenko