If you have more than one copy of React DevTools installed and enabled (e.g. the version in the Chrome store and a locally built version) they can interfere with each other.

DevTools should detect this case and warn by showing a dialog in the DevTools UI and/or by logging to the console.

Note that we _should not warn_ if a related tool like Fast Refresh is present, only another copy of DevTools.
syncSavedPreferences();
  createPanelIfReactLoaded();
}
chrome.devtools.network.onNavigated.addListener(checkPageForReact);
// Check to see if React has loaded once per second in case React is added
// after page load
const loadCheckInterval = setInterval(function() {
  createPanelIfReactLoaded();
}, 1000);
createPanelIfReactLoaded();