react: useEffect causes 'callback is not a function' exception

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

What is the current behavior?

useEffect results in the following exception in the console:

Uncaught TypeError: callback is not a function
    at flushFirstCallback (scheduler.development.js:348)
    at flushWork (scheduler.development.js:441)
    at MessagePort.channel.port1.onmessage (scheduler.development.js:188)

I am unable to isolate the problem enough to create a sandbox that reproduces it. I am posting it here in case there is still some value in it (it seems slightly related to https://github.com/react-navigation/react-navigation/issues/5851, https://github.com/gaearon/overreacted.io/issues/460 and even https://github.com/facebook/react/issues/15194). This is my component:

const RemoteControlledSliderRaw = ({ activeIndex, currentlyDragging, className, children }) => {
	const [forcedX, setForcedX] = React.useState(null);

	React.useEffect(() => {
		if (currentlyDragging) {
			window._animateItem.update = setForcedX;
		} else {
			if (window._animateItem.update) {
				setForcedX(null);
				window._animateItem.update = null;
			}
		}
	}, [currentlyDragging]);

	return (
		<div>
			<SliderCore activeIndex={activeIndex} forcedX={forcedX} className={className}>
				{children}
			</SliderCore>
		</div>
	);
};

What might be interesting is that I set a global object to point to a setState setter. That can be called from the outside. I am not sure exactly how the exception occurs, but if I comment out the entire useEffect bit, it goes away.

What is the expected behavior? No exception. Or at least one that provides some explanation as to what is wrong.

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

16.8.6. I don’t know if this worked with earlier versions.