I am trying to deploy Myfaces 2.3 base application in WAS 8.5.5.16 with Java 8 but facing below mention error.
0000005c AbstractFaces E An error occured while initializing MyFaces: Class com.ibm.ws.jsf.config.annotation.WASMyFacesAnnotationProvider is no org.apache.myfaces.spi.AnnotationProvider java.lang.IllegalArgumentException: Class com.ibm.ws.jsf.config.annotation.WASMyFacesAnnotationProvider is no org.apache.myfaces.spi.AnnotationProvider at org.apache.myfaces.shared.util.ClassUtils.buildApplicationObject(ClassUtils.java:567) at org.apache.myfaces.shared.util.ClassUtils.buildApplicationObject(ClassUtils.java:534) at org.apache.myfaces.spi.impl.DefaultAnnotationProviderFactory.resolveAnnotationProviderFromService(DefaultAnnotationProviderFactory.java:138) at org.apache.myfaces.spi.impl.DefaultAnnotationProviderFactory.createAnnotationProvider(DefaultAnnotationProviderFactory.java:93) at org.apache.myfaces.spi.impl.DefaultAnnotationProviderFactory.getAnnotationProvider(DefaultAnnotationProviderFactory.java:62) at org.apache.myfaces.config.annotation.AnnotationConfigurator.createFacesConfig(AnnotationConfigurator.java:90) at org.apache.myfaces.config.DefaultFacesConfigurationProvider.getAnnotationsFacesConfig(DefaultFacesConfigurationProvider.java:201) at org.apache.myfaces.config.DefaultFacesConfigurationMerger.getFacesConfigData(DefaultFacesConfigurationMerger.java:92) at org.apache.myfaces.config.FacesConfigurator.configure(FacesConfigurator.java:603) at org.apache.myfaces.webapp.AbstractFacesInitializer.buildConfiguration(AbstractFacesInitializer.java:456) at org.apache.myfaces.webapp.Jsp21FacesInitializer.initContainerIntegration(Jsp21FacesInitializer.java:70) at org.apache.myfaces.webapp.AbstractFacesInitializer.initFaces(AbstractFacesInitializer.java:190) at org.apache.myfaces.webapp.StartupServletContextListener.contextInitialized(StartupServletContextListener.java:103) at com.ibm.ws.webcontainer.webapp.WebApp.notifyServletContextCreated(WebApp.java:1736) at com.ibm.ws.webcontainer.webapp.WebAppImpl.initialize(WebAppImpl.java:415) at com.ibm.ws.webcontainer.webapp.WebGroupImpl.addWebApplication(WebGroupImpl.java:88) at com.ibm.ws.webcontainer.VirtualHostImpl.addWebApplication(VirtualHostImpl.java:171) at com.ibm.ws.webcontainer.WSWebContainer.addWebApp(WSWebContainer.java:904) at com.ibm.ws.webcontainer.WSWebContainer.addWebApplication(WSWebContainer.java:789) at com.ibm.ws.webcontainer.component.WebContainerImpl.install(WebContainerImpl.java:427) at com.ibm.ws.webcontainer.component.WebContainerImpl.start(WebContainerImpl.java:719) at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:1211) at com.ibm.ws.runtime.component.DeployedApplicationImpl.fireDeployedObjectStart(DeployedApplicationImpl.java:1462) at com.ibm.ws.runtime.component.DeployedModuleImpl.start(DeployedModuleImpl.java:641) at com.ibm.ws.runtime.component.DeployedApplicationImpl.start(DeployedApplicationImpl.java:1040) at com.ibm.ws.runtime.component.ApplicationMgrImpl.startApplication(ApplicationMgrImpl.java:795) at com.ibm.ws.runtime.component.ApplicationMgrImpl$5.run(ApplicationMgrImpl.java:2279) at com.ibm.ws.security.auth.ContextManagerImpl.runAs(ContextManagerImpl.java:5482) at com.ibm.ws.security.auth.ContextManagerImpl.runAsSystem(ContextManagerImpl.java:5698) at com.ibm.ws.security.core.SecurityContext.runAsSystem(SecurityContext.java:255) at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:2284) at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.start(CompositionUnitMgrImpl.java:436) at com.ibm.ws.runtime.component.CompositionUnitImpl.start(CompositionUnitImpl.java:123) at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.start(CompositionUnitMgrImpl.java:379) at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.access$500(CompositionUnitMgrImpl.java:127) at com.ibm.ws.runtime.component.CompositionUnitMgrImpl$CUInitializer.run(CompositionUnitMgrImpl.java:985) at com.ibm.wsspi.runtime.component.WsComponentImpl$_AsynchInitializer.run(WsComponentImpl.java:524) at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1892)
WebSphere 8.5.5 by default provides the MyFaces JSF 2.0 implementation. This IllegalArgumentException suggests that the WAS-provided JSF implementation is still enabled, and that the MyFaces 2.3 implementation you're providing with your app is conflicting with it.
You need to follow IBM's instructions[1] for using a "third-party JSF implementation": configure the server to use Sun RI 1.2 for JSF instead of "default" or "MyFaces", and provide your MyFaces 2.3 implementation and its dependencies as an isolated shared library.