After the redux upgrade, error message appeared:

Uncaught Error: It looks like you are passing several store enhancers to createStore(). This is not supported. Instead, compose them together to a single function.
    at createStore (redux.js:66)
    at generateStore (index.js:22)

According to https://github.com/zalmoxisus/redux-devtools-extension the redux devtools setup for a store with middleware is different from the current implementation