Change:
); }, ); <ins> // Regression test for https://github.com/facebook/react/issues/14188 it('can call findDOMNode() in a suspended component commit phase', async () => { const log = []; const Lazy = React.lazy( () => new Promise(resolve => resolve({ default() { return 'lazy'; }, }), ), ); class Child extends React.Component { componentDidMount() { log.push('cDM ' + this.props.id); ReactDOM.findDOMNode(this); } componentDidUpdate() { log.push('cDU ' + this.props.id); ReactDOM.findDOMNode(this); } render() { return 'child'; } } const buttonRef = React.createRef(); class App extends React.Component { state = { suspend: false, }; handleClick = () => { this.setState({suspend: true}); }; render() { return ( <React.Suspense fallback="Loading"> <Child id="first" /> <button ref={buttonRef} onClick={this.handleClick}> Suspend </button> <Child id="second" /> {this.state.suspend && <Lazy />} </React.Suspense> ); } } ReactDOM.render(<App />, container); expect(log).toEqual(['cDM first', 'cDM second']); log.length = 0; buttonRef.current.dispatchEvent(new MouseEvent('click', {bubbles: true})); await Lazy; expect(log).toEqual(['cDU first', 'cDU second']); }); </ins> });

Discussion:
<!-- Note: if the issue is about documentation or the website, please file it at: --Do you want to request a feature or report a bug? Bug What is the current behavior? I have a component which listens for resize events (via a BlueprintJS ResizeSensor). When loading a component dynamically with / , an exception occurs as the resize sensor appears to be unmounted: The resize sensor . Demo: Related: What is the expected behavior? No exception is thrown. Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React? Tested with: React 16.6.1, fails React 16.6.0, works
Can you test if it works on master?
Nope, it's broken on master, and after bisecting, I confirmed the regression was caused by EDIT: Something else I found is that before the regression, doesn't execute, but now it does. EDIT 2: Yeah, throws when invoked with a suspended component, here's how you can reproduce. This is true both before and after the aforementioned PR, so in any case it looks like it helped us discover this :smile:
EDIT: Something else I found is that before the regression, ResizeSensor.componentDidUpdate doesn't execute, but now it does. This sounds like a separate problem, can you provide a test case for it?
Here's a minimal repro with ReactDOM:
Okay, so a part of this is covered by It got first broken by and got fixed in . However I think repro case in might be a separate issue. Looking into it.
This sounds like a separate problem, can you provide a test case for it? Welp, turns out I'm wrong, I actually made a mistake when mocking which resulted in it not being called :stuckouttongueclosedeyes:
Another reproducible example: When does it throw: 16.6.0: never 16.6.1: on every "display lazy" click 16.7.0 until 16.8.6: on every "display lazy" click if the number of "force update" clicks is odd (meaning even number of render?)
This was likely fixed in Can you verify on master?
Yes, current fixes for me.
This will get into the next release then.
Seems it still happens.

~I tried to get mini reproduce but it seems happened in complex environment.~ User report reproduce: Quick click the nav item will throw with ref: Update: Create a mini reproduce about this:
Sorry, we didn’t release the fix yet.
any ETA on when this will be available?
We are blocked by this, too (without a pretty significant workaround). Any sense of a release timeframe? Is there some way to find out (in general) when the "next" release is? Sorry if this is covered somewhere.. For the record, this is surfacing for us through Semantic UI React Dropdown. So we're beholden to them as well, but they point us here for the fix. :)
any new updates?
We've published of all packages, which includes this fix. It is likely to be a release candidate for . You can give it a try now and see whether it resolves the issue for you. Thanks.
(You should still ask packages to migrate away from though as it's eventually going to get deprecated.)
0 hadn't fix this bug!
All reproductions linked in this issue ( and ) no longer crash with 16.9. If you still encounter this error message with 16.9 please open a new issue.