This snippet here: .then( response => response.json(), // Do not use catch, because that will also catch // any errors in the dispatch and resulting render, // causing a loop of 'Unexpected batch number' errors. // https://github.com/facebook/react/issues/6895 error => console.log('An error occurred.', error) ) I understand the warning not to use .catch(fn) , since it swallows exceptions, but .then(_, fn) , as used above, also swallows the exception.