weblogic.application.ModuleException: java.lang.ClassNotFoundException: org.apache.log4j.Logger.

Hello Weblogic gurus,

I get this error while deploying an application on weblogic server 12.1.3, oracle linux 6.5 and jdk1.7.0_55.

weblogic.application.ModuleException: java.lang.ClassNotFoundException: org.apache.log4j.Logger

        at weblogic.application.internal.ExtensibleModuleWrapper.prepare(ExtensibleModuleWrapper.java:114)

        at weblogic.application.internal.flow.ModuleListenerInvoker.prepare(ModuleListenerInvoker.java:100)

        at weblogic.application.internal.flow.ModuleStateDriver$1.next(ModuleStateDriver.java:175)

        at weblogic.application.internal.flow.ModuleStateDriver$1.next(ModuleStateDriver.java:170)

        at weblogic.application.utils.StateMachineDriver$ParallelChange.run(StateMachineDriver.java:80)

        at weblogic.work.ContextWrap.run(ContextWrap.java:40)

        at weblogic.work.SelfTuningWorkManagerImpl$WorkAdapterImpl.run(SelfTuningWorkManagerImpl.java:548)

        at weblogic.work.ExecuteThread.execute(ExecuteThread.java:311)

        at weblogic.work.ExecuteThread.run(ExecuteThread.java:263)