I am adding the component dynamically with the help of require.ensure() of ES6 and the getComponent() of the react-router. I am getting the above error once I am opening separate tab for the each record having the same key for example "A". My dynamic Loading is like this:

 require.ensure([], (require) => { 
     const req = require('./components/A).default 
     const reducer= require('./modules').default
     injectReducer(store, {
         key: 'A',
         reducer
     })
     cb(null, req)
 })

My code for the createstore() is like this:

export const makeRootReducer = (asyncReducers) => {
  return combineReducers({
    B,
    C,
    ...asyncReducers
  })
}
export const injectReducer = (store, { key, reducer }) => {
  if (Object.hasOwnProperty.call(store.asyncReducers, key))return
  store.asyncReducers[key] = reducer
  store.replaceReducer(makeRootReducer(store.asyncReducers))
}

Now the issue is that on browser tab opening except the first time it is showing the warning as:

Unexpected key " A" found in previous state received by the reducer Expected to find one of the known reducer keys instead: "B", "C". Unexpected keys will be ignored.

If I will pass initially Key 'A' combineReducers() then this warning will go off. But this combineReducers() is global and it will keep the state of the reducers so that I don't want to pass this Key on the initial load. How can I solve this warning please assist me.