[SOLVED] ClassNotFoundException for com.bea.content.manager.internal.ContentUpgradeListener when attempting to start application in Weblogic 10.2

I'm getting the following error when attempting to move an application from a state of "Prepared" to "Active":

weblogic.management.DeploymentException:
        at weblogic.application.internal.flow.BaseLifecycleFlow$CreateListenerAction.run(BaseLifecycleFlow.java:171)
        at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
        at weblogic.security.service.SecurityManager.runAs(Unknown Source)
        at weblogic.application.internal.flow.BaseLifecycleFlow$BaseAction.invoke(BaseLifecycleFlow.java:99)
        at weblogic.application.internal.flow.HeadLifecycleFlow.createListener(HeadLifecycleFlow.java:117)
        at weblogic.application.internal.flow.HeadLifecycleFlow.createListener(HeadLifecycleFlow.java:103)
        at weblogic.application.internal.flow.HeadLifecycleFlow.createListeners(HeadLifecycleFlow.java:172)
        at weblogic.application.internal.flow.HeadLifecycleFlow.prepare(HeadLifecycleFlow.java:277)
        at weblogic.application.internal.BaseDeployment$1.next(BaseDeployment.java:615)
        at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:26)
        at weblogic.application.internal.BaseDeployment.prepare(BaseDeployment.java:191)
        at weblogic.application.internal.DeploymentStateChecker.prepare(DeploymentStateChecker.java:147)
        at weblogic.deploy.internal.targetserver.AppContainerInvoker.prepare(AppContainerInvoker.java:61)
        at weblogic.deploy.internal.targetserver.operations.ActivateOperation.createAndPrepareContainer(ActivateOperation.java:189)
        at weblogic.deploy.internal.targetserver.operations.StartOperation.createAndPrepareContainer(StartOperation.java:88)
        at weblogic.deploy.internal.targetserver.operations.AbstractOperation.prepare(AbstractOperation.java:217)
        at weblogic.deploy.internal.targetserver.DeploymentManager.handleDeploymentPrepare(DeploymentManager.java:719)
        at weblogic.deploy.internal.targetserver.DeploymentManager.prepareDeploymentList(DeploymentManager.java:1186)
        at weblogic.deploy.internal.targetserver.DeploymentManager.handlePrepare(DeploymentManager.java:248)
        at weblogic.deploy.internal.targetserver.DeploymentServiceDispatcher.prepare(DeploymentServiceDispatcher.java:157)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.doPrepareCallback(DeploymentReceiverCallbackDeliverer.java:12)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.access$000(DeploymentReceiverCallbackDeliverer.java:45)
        at weblogic.work.SelfTuningWorkManagerImpl$WorkAdapterImpl.run(SelfTuningWorkManagerImpl.java:464)
        at weblogic.work.ExecuteThread.execute(ExecuteThread.java:200)
        at weblogic.work.ExecuteThread.run(ExecuteThread.java:172)
java.lang.ClassNotFoundException: com.bea.content.manager.internal.ContentUpgradeListener
        at weblogic.utils.classloaders.GenericClassLoader.findLocalClass(GenericClassLoader.java:286)
        at weblogic.utils.classloaders.GenericClassLoader.findClass(GenericClassLoader.java:259)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
        at weblogic.utils.classloaders.GenericClassLoader.loadClass(GenericClassLoader.java:179)
        at weblogic.application.internal.flow.BaseLifecycleFlow$CreateListenerAction.run(BaseLifecycleFlow.java:135)
        at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
        at weblogic.security.service.SecurityManager.runAs(Unknown Source)
        at weblogic.application.internal.flow.BaseLifecycleFlow$BaseAction.invoke(BaseLifecycleFlow.java:99)
        at weblogic.application.internal.flow.HeadLifecycleFlow.createListener(HeadLifecycleFlow.java:117)
        at weblogic.application.internal.flow.HeadLifecycleFlow.createListener(HeadLifecycleFlow.java:103)
        at weblogic.application.internal.flow.HeadLifecycleFlow.createListeners(HeadLifecycleFlow.java:172)
        at weblogic.application.internal.flow.HeadLifecycleFlow.prepare(HeadLifecycleFlow.java:277)
        at weblogic.application.internal.BaseDeployment$1.next(BaseDeployment.java:615)
        at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:26)
        at weblogic.application.internal.BaseDeployment.prepare(BaseDeployment.java:191)
        at weblogic.application.internal.DeploymentStateChecker.prepare(DeploymentStateChecker.java:147)
        at weblogic.deploy.internal.targetserver.AppContainerInvoker.prepare(AppContainerInvoker.java:61)
        at weblogic.deploy.internal.targetserver.operations.ActivateOperation.createAndPrepareContainer(ActivateOperation.java:189)
        at weblogic.deploy.internal.targetserver.operations.StartOperation.creatAndPrepareContainer(StartOperation.java:88)
        at weblogic.deploy.internal.targetserver.operations.StarOperation.doPrepare(StartOperation.java:99)
        at weblogic.deploy.internal.targetserver.operations.AbstractOperation.prepare(AbstractOperation.java:217)
        at weblogic.deploy.internal.targetserver.DeploymentManager.handleDeploymentPepare(DeploymentManager.java:719)
        at weblogic.deploy.internal.targetserver.DeploymentManager.prepareDeploymentList(DeploymentManager.java:1186)
        at weblogic.deploy.internal.targetserver.DeploymentManager.handlePrepare(DeploymentManager.java:248)
        at weblogic.deploy.internal.targetserver.DeploymentServiceDispatcher.prepare(DeploymentServiceDispatcher.java:157)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.doPrepareCallback(DeploymentReceiverCallbackDeliverer.java:157)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.access$000(DeploymentReceiverCallbackDeliverer.java:12)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer$1.run(DeploymentReceiverCallbackDeliverer.java:45)
        at weblogic.work.SelfTuningWorkManagerImpl$WorkAdapterImpl.run(SelfTuningWorkManagerImpl.java:464)
        at weblogic.work.ExecuteThread.execute(ExecuteThread.java:200)
        at weblogic.work.ExecuteThread.run(ExecuteThread.java:172)

I found the jar file that this class is in, and it is present in the weblogic directory. That same weblogic installation will successfully run the same ear file I'm trying to deploy and run here using a different weblogic domain. So, I'm pretty sure that the problem is not with the weblogic installation and not with the ear, but with the domain configuration.

Update: I've stopped getting this error and am not entirely sure why. I have no way to judge the quality of other answers here but hopefully others will find this thread helpful.