An unknown bug

[Anekenonso]

I was following the tutorial on the website half way down the finishing line I got this error in my dev console

TypeError: Cannot read property '0' of undefined
Board.renderSquare
http://localhost:3000/static/js/main.chunk.js:185:34
182 | var _this2 = this;
183 |
184 | return react__WEBPACK_IMPORTED_MODULE_6___default.a.createElement(Square, {
185 | value: this.props.squares[i],
| ^ 186 | onClick: function onClick() {
187 | return _this2.onClick(i);
188 | },

and it stopped working