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Report a bug.

What is the current behavior?

New dev tools are working fine. But I have a particular component that, when it mounts, the dev tools no longer can inspect anything about it. When I select it, the right hand side just says "Loading..." and nothing ever loads.

As you can see from the gif above, before I click on that particular component that seems to break, I have no errors in my console. But as soon as I click on the component that breaks (or any of its children) the number of console errors goes up by one.

The error in the console looks like this:

backend.js:1 Uncaught DOMException: Failed to execute 'postMessage' on 'Window': #<HTMLAllCollection> could not be cloned.
    at Object.send (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/backend.js:1:94424)
    at chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/backend.js:9:5785

Hard to provide steps to reproduce this since it's a custom component with business-specific logic (so can't provide the code). But I tried google-ing this problem and error and nothing showed up. So figured posting it here might help if others out there on the interwebs are having the same issue and they can comment here.

What is the expected behavior?

Inspecting any mounted component will work.

Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?

Currently on react/react-dom 16.3 and the previous dev tools worked just fine. I could inspect any component and see it's data. But the latestest update broke that.