Error: Minified React error #321

Whenever I write a useEffect() inside a component function of my block plugin, the edit page goes blank and the console logs the message:

react_devtools_backend.js:4026 Error: Minified React error #321; visit https://reactjs.org/docs/error-decoder.html?invariant=321 for the full message or use the non-minified dev environment for full errors and additional helpful warnings.
    at Object.it (react-dom.min.js?ver=17.0.1:9:43163)
    at e.useState (react.min.js?ver=17.0.1:9:10899)
    at Prompt (Prompt.js:5:35)
    at N (element.min.js?ver=3dfdc75a0abf30f057df44e9a39abe5b:2:9552)
    at U (element.min.js?ver=3dfdc75a0abf30f057df44e9a39abe5b:2:10502)
    at N (element.min.js?ver=3dfdc75a0abf30f057df44e9a39abe5b:2:9284)
    at lr (blocks.min.js?ver=658a51e7220626e26a92a46af5c2e489:3:111294)
    at blocks.min.js?ver=658a51e7220626e26a92a46af5c2e489:3:137935
    at xn (blocks.min.js?ver=658a51e7220626e26a92a46af5c2e489:3:138073)
    at blocks.min.js?ver=658a51e7220626e26a92a46af5c2e489:3:139086

The component:

import React, { useState, useEffect } from "react";
import axios from "axios";

function Prompt(props) {
  const [data, setData] = useState({ hits: [] });

  useEffect(() => {
    const fetchData = async () => {
      const result = await axios(
        "http://my-site-test.local/wp-json/wp/v2/posts?_fields[]=title"
      );

      setData(result.data);
    };

    fetchData();
  }, []);

  console.log(data);

  return (
    <>
      <h5>Hello World</h5>
    </>
  );
}

export default Prompt;

I tried to delete node_modules and reinstall to no avail…