error C2259: 'CSceneObjMediator' : cannot instantiate abstract class

Question

I am getting the following error:

error C2259: 'CSceneObjMediator' : cannot instantiate abstract class

for the following code:

    CSceneObjMediator* CSceneObjServerMgr::CreateSceneObjMediator()
{
    uint32 uId = GetobjId();

    CSceneObjServer* pObj = PPE_NEW_T (CSceneObjServer, MEMCATEGORY_GENERAL, "")(uId);
    CSceneObjMediator* pMediator = PPE_NEW_T(CSceneObjMediator, MEMCATEGORY_GENERAL, "")(pObj);
    return pMediator;
}

And the other following error:

error C2259: 'CSceneObjDictator' : cannot instantiate abstract class

for the following code:

    CSceneObjDictator* CSceneObjServerMgr::CreateSceneObjDictator()
{
    uint32 uId = GetobjId();
    CSceneObjServer* pObj = PPE_NEW_T (CSceneObjServer, MEMCATEGORY_GENERAL, "")(uId);
    CSceneObjDictator* pDictator = PPE_NEW_T (CSceneObjDictator, MEMCATEGORY_GENERAL, "")(pObj);
    return pDictator;
}

Any help appreciated.