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**Do you want to request a *feature* or report a *bug*?**
Bug

**What is the current behavior?**
The profiler tab only shows this message even though I have a version greater than 16.5.

![Screen Shot 2019-09-06 at 13 26 47](https://user-images.githubusercontent.com/5483459/64444238-0d706c00-d0aa-11e9-8d32-810465a13433.png)


Something strange on the console is this message and just appears when the extension is active.

![Screen Shot 2019-09-06 at 13 25 17](https://user-images.githubusercontent.com/5483459/64444170-e74acc00-d0a9-11e9-8b7c-acaa31e50cea.png)

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
React **16.9.0**
React DevTools **4.0.6-a39d9c3**

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */
import Symbol from 'es6-symbol';
import LRU from 'lru-cache';
import {
  TREE_OPERATION_ADD,
  TREE_OPERATION_REMOVE,
  TREE_OPERATION_REORDER_CHILDREN,
  TREE_OPERATION_UPDATE_TREE_BASE_DURATION,
} from './constants';
import {ElementTypeRoot} from 'react-devtools-shared/src/types';
import {
  LOCAL_STORAGE_FILTER_PREFERENCES_KEY,
  LOCAL_STORAGE_SHOULD_PATCH_CONSOLE_KEY,
} from './constants';
import {ComponentFilterElementType, ElementTypeHostComponent} from './types';
import {
  ElementTypeClass,
  ElementTypeForwardRef,