fix ts-loader version from latest ver to 3.5, if you use webpack 3 2018年6月19日 922 × 398 これ。「TypeScript & Webpack3」Module build failed: Error: You may be using an old version of webpack; please check you’re using at least version 4 fix ts-loader version from latest ver to 3.5, if you use webpack 3 fix ts-loader version from latest ver to 3.5, if you use webpack 3