我正在websphere 8.5.5上部署我的应用程序。 当我从控制台启动应用程序时，我在systemErr.out文件中遇到以下stacktrace错误。 你知道这个例外的原因是什么吗？
com.ibm.ws.exception.RuntimeWarning: com.ibm.ws.webcontainer.exception.WebAppNotLoadedException: Failed to load webapp: Failed to load webapp: null
at com.ibm.ws.webcontainer.component.WebContainerImpl.install(WebContainerImpl.java:432)
at com.ibm.ws.webcontainer.component.WebContainerImpl.start(WebContainerImpl.java:718)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:1175)
at com.ibm.ws.runtime.component.DeployedApplicationImpl.fireDeployedObjectStart(DeployedApplicationImpl.java:1370)
at com.ibm.ws.runtime.component.DeployedModuleImpl.start(DeployedModuleImpl.java:639)
at com.ibm.ws.runtime.component.DeployedApplicationImpl.start(DeployedApplicationImpl.java:968)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.startApplication(ApplicationMgrImpl.java:774)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.startApplicationDynamically(ApplicationMgrImpl.java:1374)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:2179)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.start(CompositionUnitMgrImpl.java:445)