While deploying into weblogic8.1 excepation is occuried can any help in this topic

Hi All,
I new to the weblogic when i deploying in the deploy module then it throwing the exception can any suggest me on this topic.

java.lang.NoClassDefFoundError: ejb/abstracts/AbstractEntityBean

at java.lang.ClassLoader.defineClass(Unknown Source)

at java.security.SecureClassLoader.defineClass(Secure ClassLoader.java:123)

at weblogic.utils.classloaders.GenericClassLoader.fin dLocalClass(GenericClassLoader.java:480)

at weblogic.utils.classloaders.GenericClassLoader.fin dClass(GenericClassLoader.java:182)

at java.lang.ClassLoader.loadClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at weblogic.utils.classloaders.GenericClassLoader.loa dClass(GenericClassLoader.java:224)

at weblogic.ejb20.deployer.EJBModule.setupEJBToImplCl assDependencies(EJBModule.java:1030)

at weblogic.ejb20.deployer.EJBModule.prepare(EJBModul e.java:481)

at weblogic.j2ee.J2EEApplicationContainer.prepareModu le(J2EEApplicationContainer.java:3149)

at weblogic.j2ee.J2EEApplicationContainer.prepareModu les(J2EEApplicationContainer.java:1590)

at weblogic.j2ee.J2EEApplicationContainer.prepare(J2E EApplicationContainer.java:1234)

at weblogic.j2ee.J2EEApplicationContainer.prepare(J2E EApplicationContainer.java:1077)

at weblogic.management.deploy.slave.SlaveDeployer$Com ponentActivateTask.prepareContainer(SlaveDeployer. java:2530)

at weblogic.management.deploy.slave.SlaveDeployer$Act ivateTask.createContainer(SlaveDeployer.java:2480)

at weblogic.management.deploy.slave.SlaveDeployer$Act ivateTask.prepare(SlaveDeployer.java:2396)

at weblogic.management.deploy.slave.SlaveDeployer.pro cessPrepareTask(SlaveDeployer.java:883)

at weblogic.management.deploy.slave.SlaveDeployer.pre pareDelta(SlaveDeployer.java:591)

at weblogic.management.deploy.slave.SlaveDeployer.pre pareUpdate(SlaveDeployer.java:500)

at weblogic.drs.internal.SlaveCallbackHandler$1.execu te(SlaveCallbackHandler.java:25)

at weblogic.kernel.ExecuteThread.execute(ExecuteThrea d.java:224)

at weblogic.kernel.ExecuteThread.run(ExecuteThread.ja va:183)

at java.lang.Thread.startThreadFromVM(Unknown Source)

--------------- nested within: ------------------

weblogic.management.ManagementException: [Deployer:149233]An unexpected error was encountered during the deployment process. - with nested exception:

[java.lang.NoClassDefFoundError: ejb/abstracts/AbstractEntityBean]

at weblogic.management.deploy.slave.SlaveDeployer.con vertThrowable(SlaveDeployer.java:1034)

at weblogic.management.deploy.slave.SlaveDeployer.acc ess$500(SlaveDeployer.java:116)
Thanks in advance.:(handshake):