React-dnd: अनकवर्ड एरर: आइटम एक ऑब्जेक्ट होना चाहिए

नमस्ते। मैंने इस बग का कोई उल्लेख खोजने की कोशिश की, लेकिन दुर्भाग्य से यहां या वेब पर कुछ भी मौजूद नहीं था।

मैंने एक परियोजना शुरू की है और इसमें बहुत ही सरल सेटअप है और जब यह त्रुटि होने पर तत्व को खींचने की कोशिश की जा रही है:
http://prntscr.com/jpfale

यह मेरा ड्रैग कंपोनेंट है:

import React from 'react';
import PropTypes from 'prop-types';
import styled from 'styled-components';
import { DragSource } from 'react-dnd';

const Container = styled.span`
  margin: 10px;
  font-size: 4rem;
  text-transform: uppercase;
  cursor: pointer;
  transition: 0.4s;

  &.is-clicked {
    color: ${({ theme }) => theme.colors.purple};
  }

  &.is-hidden {
    opacity: 0;
  }
`;

const spec = {
  beginDrag(props) {
    console.log('test');
    return {};
  },
};

const WordItem = ({
  children,
  item,
  isHidden,
  handleClick,
  connectDragSource,
}) => {
  return connectDragSource(
    <span>
      <Container
        className={item.clicked ? 'is-clicked' : isHidden}
        onClick={handleClick}
      >
        {children}
      </Container>
    </span>,
  );
};

WordItem.propTypes = {
  children: PropTypes.string.isRequired,
  item: PropTypes.objectOf(PropTypes.any).isRequired,
  isHidden: PropTypes.string.isRequired,
  handleClick: PropTypes.func.isRequired,
};

export default DragSource('word', spec, (connect, monitor) => ({
  connectDragSource: connect.dragSource(),
  isDragging: monitor.isDragging(),
  dropResult: monitor.getDropResult(),
  canDrag: monitor.canDrag(),
}))(WordItem);

संदर्भ से जुड़ा कंटेनर:

export default DragDropContext(HTML5Backend)(App);

मैंने पहले से ही प्रतिक्रिया-डंड के साथ एक परियोजना की थी, लेकिन यह पहली बार है जब मैंने इस मुद्दे को देखा। यहाँ मेरा package.json है अगर इस समस्या को पुस्तकालयों की अनुकूलता के साथ जोड़ा जा सकता है:

{
  "name": "",
  "version": "1.0.0",
  "description": "npm i -g prettier",
  "main": "index.js",
  "scripts": {
    "clean": "rimraf dist",
    "dev": "cross-env NODE_ENV=development node devServer.js",
    "build": "npm run clean && cross-env NODE_ENV=production webpack --config=webpack.build.config.js -p && node productionServer.js",
    "flow": "flow"
  },
  "author": "",
  "license": "ISC",
  "browserslist": [
    "last 5 versions",
    "not ie < 11"
  ],
  "prettier": {
    "singleQuote": true,
    "trailingComma": "all"
  },
  "dependencies": {
    "axios": "^0.18.0",
    "babel-plugin-styled-components": "^1.5.1",
    "es6-promise": "^4.2.4",
    "prop-types": "^15.6.1",
    "rc-slider": "^8.6.1",
    "react": "^16.3.2",
    "react-dnd": "^3.0.2",
    "react-dnd-html5-backend": "^3.0.2",
    "react-dom": "^16.3.2",
    "react-motion": "^0.5.2",
    "react-redux": "^5.0.7",
    "react-router-dom": "^4.2.2",
    "redux": "^4.0.0",
    "redux-thunk": "^2.2.0",
    "styled-components": "^3.2.6",
    "svg-inline-loader": "^0.8.0",
    "xml2js": "^0.4.19"
  },
  "devDependencies": {
    "autoprefixer": "^8.3.0",
    "babel-core": "^6.26.0",
    "babel-eslint": "^8.2.3",
    "babel-loader": "^7.1.4",
    "babel-plugin-transform-class-properties": "^6.24.1",
    "babel-plugin-transform-object-rest-spread": "^6.26.0",
    "babel-plugin-transform-runtime": "^6.23.0",
    "babel-preset-env": "^1.6.1",
    "babel-preset-flow": "^6.23.0",
    "babel-preset-react": "^6.24.1",
    "browserslist": "^3.2.4",
    "compression-webpack-plugin": "^1.1.11",
    "cross-env": "^5.1.4",
    "css-loader": "^0.28.11",
    "eslint": "^4.19.1",
    "eslint-config-airbnb": "^16.1.0",
    "eslint-config-prettier": "^2.9.0",
    "eslint-plugin-import": "^2.11.0",
    "eslint-plugin-jsx-a11y": "^6.0.3",
    "eslint-plugin-prettier": "^2.6.0",
    "eslint-plugin-react": "^7.7.0",
    "express": "^4.16.3",
    "extract-text-webpack-plugin": "^4.0.0-beta.0",
    "file-loader": "^1.1.11",
    "flow-bin": "^0.70.0",
    "html-webpack-plugin": "^3.2.0",
    "image-webpack-loader": "^4.2.0",
    "node-sass": "^4.8.3",
    "postcss-loader": "^2.1.4",
    "prettier-eslint": "^8.8.1",
    "react-hot-loader": "^4.0.0",
    "rimraf": "^2.6.2",
    "sass-loader": "^7.0.1",
    "style-loader": "^0.20.3",
    "url-loader": "^1.0.1",
    "webpack": "^4.6.0",
    "webpack-cli": "^2.1.2",
    "webpack-dev-middleware": "^3.1.2",
    "webpack-hot-middleware": "^2.22.1"
  }
}

कृपया इस समस्या को हल करने में मदद करें।