React's useOptimistic Hook Can Silently Mislead Users When Server Actions Fail

React's useOptimistic hook updates the UI instantly before a server response, but a common implementation flaw leaves error handling entirely unaddressed. When a server action fails due to a network issue, database error, or authorization rejection, the optimistic UI briefly shows a false success state before quietly reverting, with no explanation given to the user. This silent revert creates a confusing experience worse than standard UI behavior, as users see a change appear and then disappear without any feedback. Developers can fix this by pairing useOptimistic with a local error state that captures and displays failure messages when the server action returns an unsuccessful result. The automatic revert mechanism in useOptimistic works as intended, but surfacing the reason for that revert to the user is the missing piece most implementations overlook.