How to fix 'The previous state received by the reducer...'?

Question

I load/update data in localStorage:

import thunk from "redux-thunk";
import {applyMiddleware, createStore} from "redux";
import {composeWithDevTools} from "redux-devtools-extension";
import reducers from "./reducers";
import {loadState, saveState} from "./localStorage";

const persistedState = loadState()
export const store = createStore(reducers, persistedState, composeWithDevTools(applyMiddleware(thunk)))
store.subscribe(() => saveState(store.getState().user.userId))

but I have error

The previous state received by the reducer has unexpected type of "string". Expected argument to be an object with the following keys: "user", "countries", "sortedCountries"

After deleting persistedState from createStore the error disappears