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.

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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
if (__DEBUG__) {
      debug('unmountFiberChildrenRecursively()', fiber);
    }
     W
    const isTimedOutSuspense =
      fiber.tag === ReactTypeOfWork.SuspenseComponent &&
      fiber.memoizedState !== null;
    let child = fiber.child;
    if (isTimedOutSuspense) {
       I
      const primaryChildFragment = fiber.child;
      const fallbackChildFragment = primaryChildFragment
        ? primaryChildFragment.sibling
        : null;
       S
      child = fallbackChildFragment ? fallbackChildFragment.child : null;
    }
    while (child !== null) {
       R
       W
      if (child.return !== null) {
        unmountFiberChildrenRecursively(child);
        recordUnmount(child, true);
      }
      child = child.sibling;
    }
  }
  function recordProfilingDurations(fiber: Fiber) {
    const id = getFiberID(getPrimaryFiber(fiber));
    const {actualDuration, treeBaseDuration} = fiber;