Cannot combine Nextjs and Slider of Material UI

[teppei-kogure]

I wrote the following script to combine Next.JS and rhf, but the following error occurs. Can this be avoided?

`import React, { useState } from "react";
import { useForm, Controller } from "react-hook-form";
import Header from "./Header";
import {
TextField,
RadioGroup,
FormControlLabel,
ThemeProvider,
Radio,
createMuiTheme,
Slider
} from "@material-ui/core";
function App() {
const { handleSubmit, reset, control, errors, getValues } = useForm({ defaultValues });
const [data, setData] = useState(null);
const handleChange = (event, newData) => {
setData(newData)
};
const marks = []
for (let i = 0; i <= 10; i++) {
marks.push({
value: i,
label: String(i)
})
}
return (

<form onSubmit={handleSubmit(data => setData(data))}className="form">

<Controller
name="manner_points"
control={control}
onChange={handleChange}
as={}
/>

    <ButtonsResult {...{ data, reset, defaultValues }} />
  </form>
  {/* <style jsx>{`
  `}</style> */}
</ThemeProvider>

);
}
export default App;`

But, When operating the Slider, I get the following error
Material-UI: A component is changing the controlled value state of Slider to be uncontrolled. Elements should not switch from uncontrolled to controlled (or vice versa). Decide between using a controlled or uncontrolled Slider element for the lifetime of the component. The nature of the state is determined during the first render, it's considered controlled if the value is not undefined.
I think it's a state-related problem, but I don't know how to fix it. Please tell me if there is any means

[bluebill1049]

sounds like you are missing defaultVlaue

[teppei-kogure]

Which side of the defult value is wrong? Or how should I fix it?

[bluebill1049]

at the Controller

[teppei-kogure]

I checked folling this url
https://codesandbox.io/s/react-hook-form-v6-controller-24gcl?file=/src/index.jsx:3473-3927

and I missed state .

[bluebill1049]

it's using defaultValues at useForm

useForm({
  defaultValues
});

so you have must miss at the defaultValues

[teppei-kogure]

Thank you very much. That helps a lot