facebook/react · warning

Could not find instance with id "${id}"

Error message

Could not find instance with id "${id}"

What it means

updateSelectedElement() in the legacy DevTools backend (for pre-Fiber React, packages/react-devtools-shared/src/backend/legacy/renderer.js) assigns the currently selected element to console global $r. It first resolves the selected id via idToInternalInstanceMap; if the map has no entry, the element is gone from the renderer's view of the tree, so DevTools logs this warning and leaves $r untouched. This is a stale-id condition: the id was valid when selected but the instance was unmounted (or the renderer re-registered) before the lookup.

Source

Thrown at packages/react-devtools-shared/src/backend/legacy/renderer.js:691

    if (internalInstance != null) {
      instance = internalInstance._instance || null;

      const element = internalInstance._currentElement;
      if (element != null && element.props != null) {
        style = element.props.style || null;
      }
    }

    return {
      instance,
      style,
    };
  }

  function updateSelectedElement(id: number): void {
    const internalInstance = idToInternalInstanceMap.get(id);
    if (internalInstance == null) {
      console.warn(`Could not find instance with id "${id}"`);
      return;
    }

    switch (getElementType(internalInstance)) {
      case ElementTypeClass:
        global.$r = internalInstance._instance;
        break;
      case ElementTypeFunction:
        const element = internalInstance._currentElement;
        if (element == null) {
          console.warn(`Could not find element with id "${id}"`);
          return;
        }

        global.$r = {
          props: element.props,
          type: element.type,
        };

View on GitHub (pinned to eafeac097b)

Solutions

1. Re-select the element in the Components tree so the id-to-instance map is fresh, then retry the inspection.
2. Freeze the UI (breakpoint, 'Emulate a focused page', or pause on unmount) so the element cannot disappear before you inspect it.
3. Upgrade the app to React 16+ so DevTools uses the Fiber backend with a more robust id map.

// Backend-internal; the equivalent guard if you drive a DevTools agent:
const renderer = agent.rendererInterfaces[rendererID];
if (renderer != null && renderer.hasElementWithId(id)) {
  // safe to inspect/select
}

When it happens

Trigger: Selecting an element in the Components tree and the component unmounting before DevTools runs updateSelectedElement (e.g. 'store as global variable' or re-selecting after an update); a hot reload replacing the root; calling inspect-at-point on a node removed by a timer or websocket update.

Common situations: Inspecting apps on React < 16 with the DevTools legacy backend while the UI keeps updating; holding an old selection across HMR; debugging components that unmount immediately after render.

Related errors

• Could not find element with id "${id}"
• Cannot not suspend ID '${suspendedSet[i]}'.
• Invalid renderer id "${rendererID}" for element "${id}"
• Invalid renderer id "${match.rendererID}" for element "${mat
• Profiling data cannot be updated while profiling is in progr

AI-assisted analysis of facebook/react@eafeac097b (2026-08-21). Data as JSON: /api/errors/89b23ca0c749d2e4. Report an issue: GitHub.