Problem with openfire debug.log

After upgrade from 3.6.x to 3.7.0 I have problem with openfire log files. Debug logging is enabled (log.debug.enabled is set to true), logfile is empty.

In nohup.log file I’ve found this:

log4j:ERROR Could not instantiate class [org.jivesoftware.openfire.gateway.util.Log4JToOpenfireAppender].

java.lang.ClassNotFoundException: org.jivesoftware.openfire.gateway.util.Log4JToOpenfireAppender

at java.net.URLClassLoader$1.run(URLClassLoader.java:200)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:188)

at java.lang.ClassLoader.loadClass(ClassLoader.java:306)

at java.lang.ClassLoader.loadClass(ClassLoader.java:251)

at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)

at java.lang.Class.forName0(Native Method)

at java.lang.Class.forName(Class.java:169)

at org.apache.log4j.helpers.Loader.loadClass(Loader.java:179)

at org.apache.log4j.helpers.OptionConverter.instantiateByClassName(OptionConverter .java:320)

at org.apache.log4j.helpers.OptionConverter.instantiateByKey(OptionConverter.java: 121)

at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:6 64)

at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:6 47)

at org.apache.log4j.PropertyConfigurator.configureRootCategory(PropertyConfigurato r.java:544)

at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:440 )

at org.apache.log4j.PropertyConfigurator.configure(PropertyConfigurator.java:367)

at org.jivesoftware.openfire.gateway.GatewayPlugin.setLoggerProperty(GatewayPlugin .java:251)

at org.jivesoftware.openfire.gateway.GatewayPlugin.(GatewayPlugin.java:58)

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessor Impl.java:39)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructor AccessorImpl.java:27)

at java.lang.reflect.Constructor.newInstance(Constructor.java:513)

at java.lang.Class.newInstance0(Class.java:355)

at java.lang.Class.newInstance(Class.java:308)

at org.jivesoftware.openfire.container.PluginManager.loadPlugin(PluginManager.java :420)

at org.jivesoftware.openfire.container.PluginManager.access$300(PluginManager.java :80)

at org.jivesoftware.openfire.container.PluginManager$PluginMonitor.run(PluginManag er.java:1067)

at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)

at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:317)

at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150)

at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$101 (ScheduledThreadPoolExecutor.java:98)

at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.runPeriodi c(ScheduledThreadPoolExecutor.java:181)

at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Schedu ledThreadPoolExecutor.java:205)

at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java: 885)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)

at java.lang.Thread.run(Thread.java:619)

log4j:ERROR Could not instantiate appender named “openfire”.

log4j:WARN No appenders could be found for logger (org.jivesoftware.util.log.util.CommonsLogFactory).

log4j:WARN Please initialize the log4j system properly.

How could I fix this problem?