May be a bug

[cfgxy]

window.event is null in IE9/IE10, this cause read type property on null at line 373

https://github.com/facebook/react/blob/9e3b772b8cabbd8cadc7522ebe3dde3279e79d9e/packages/react-dom/src/client/ReactDOMHostConfig.js#L370-L373

[guillaumebrunerie]

Is this in React 18? Note that IE is not supported anymore: https://reactjs.org/blog/2022/03/08/react-18-upgrade-guide.html#dropping-support-for-internet-explorer

[gaearon]

This can't be true — window.event has been supported since IE4. https://developer.mozilla.org/en-US/docs/Web/API/Window/event

[gaearon]

Oh you're saying it's null rather than undefined?

[yeliex]

yes, window.event in ie would be undefined. could add a fix for this

[TrAndreiR]

Any update on this issue? I am getting this issue in React 18.

[coderup2021]

I also getting this issue in React 18

[github-actions[bot]]

This issue has been automatically marked as stale. If this issue is still affecting you, please leave any comment (for example, "bump"), and we'll keep it open. We are sorry that we haven't been able to prioritize it yet. If you have any new additional information, please include it with your comment!

[github-actions[bot]]

Closing this issue after a prolonged period of inactivity. If this issue is still present in the latest release, please create a new issue with up-to-date information. Thank you!