How to Fix FinalizationRegistry Error in React

A FinalizationRegistry Error in React usually signals a straightforward configuration problem. Here's exactly how to fix it.

Understanding the Problem

FinalizationRegistry errors typically occur in environments that don't support this API or when callbacks reference already-garbage-collected objects. It was introduced in ES2021 and requires Node.js 14.6+ or modern browsers.

Solution

The key is to use useEffect cleanup instead of FinalizationRegistry for React component lifecycles:

function useResourceCleanup(resource) {
  // Don't rely on FinalizationRegistry in React
  // Use useEffect cleanup instead
  useEffect(() => {
    const handle = resource.acquire();
    return () => {
      handle.release();
    };
  }, [resource]);
}

// If you must use FinalizationRegistry, keep it outside components
const registry = typeof FinalizationRegistry !== "undefined"
  ? new FinalizationRegistry((cb) => cb())
  : null;

Common Pitfall

Don't overlook your CI/CD pipeline — sometimes the fix works locally but the deployment environment has different defaults. Make sure your React configuration is explicit rather than relying on defaults. Review your React project's dependency tree after applying this fix. Outdated packages are a common source of subtle incompatibilities.

Confirming It Works

To confirm the fix is working, check your React application logs for any remaining error traces. You should see clean request/response cycles without the previous error. Deploy to a staging environment to verify the fix holds under production-like conditions.

Going Forward

Tip: Use Bugsly to automatically detect and alert you to React errors like this in production before your users notice them.