Describe what you were doing when the bug occurred:
1. I was using the devtools to investigate some performance issues w/ an app I help maintain
2. I had just turned on the "Record why each component rendered while profiling" checkbox
3. I ran a profile while navigating on the underlying page

The react profiler tab in the devtools gave this error, I think as I clicked the record icon to stop recording the profile.

---------------------------------------------
Please do not remove the text below this line
---------------------------------------------

DevTools version: 4.5.0-355970aa4

Call stack: at N (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40:160881)
    at j (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40:160015)
    at j (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40:159939)
    at j (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40:159939)
    at j (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40:159939)
    at j (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40:159939)
    at j (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40:159939)
    at j (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40:159939)
    at j (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40:159939)
    at j (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40:159939)

Component stack: in ec
    in div
    in div
    in div
    in So
    in Unknown
    in n
    in Unknown
    in div
    in div
    in rl
    in Ze
    in fn
    in Ga
    in _s
} else {
      while (node.return) {
        node = node.return;
      }
    }
    if (node.tag === HostRoot) {
       T
       r
      return MOUNTED;
    }
     If we didn't hit the root, that means that we're in an disconnected tree
     that has been u
    return UNMOUNTED;
  }
   This function is copied from React and should be kept in sync:
   https:github.com/facebook/react/blob/master/packages/react-reconciler/src/ReactFiberTreeReflection.js
   It would be nice if we updated React to inject this function directly (vs just indirectly via findDOMNode).
   BEGIN copied code
  function findCurrentFiberUsingSlowPathById(id: number): Fiber | null {
    const fiber = idToFiberMap.get(id);
    if (fiber == null) {
      console.warn(`Could not find Fiber with id "${id}"`);
      return null;
    }
    const alternate = fiber.alternate;
    if (!alternate) {
       I
      const state = isFiberMountedImpl(fiber);
      if (state === UNMOUNTED) {
        throw Error('Unable to find node on an unmounted component.');