Can only update a mounted or mounting component. This usually means you called setState, replaceState, or forceUpdate on an unmounted component. This is a no-op. Please check the code for the AnimateNumber component.

[marlti7]

When I go back to a page，find this problem

[marlti7]

I found a solution， when componentWillUnmount need clearout Timer

[uglyspoon]

@marlti7
by add

 componentWillUnmount () {
    clearTimeout(Timer);
  }

not work for me

[uglyspoon]

find a way to fix this bug , this bug because the Timer won't unmount when your component unmounts.
so set clearTimeout when componentWillUnmount();
code like this :

startAnimate() {
  this.timer = Timer.setTimeout(() => {
    console.log('I do not leak!');
  }, 500);
}

componentWillUnmount() {
  clearTimeout(this.timer);
}

happy coding !

[marquesm91]

@uglyspoon I just add it on the bottom of AnimatedNumber class

componentWillUnmount () {
  clearTimeout(Timer);
}

And works for me. Now, when I go to another screen I am fine and the warning doesn't show anymore.