Html Webpack Plugin:
<pre>
Error: Child compilation failed:
Module not found: Error: Can't resolve '/app/perkoupon-main/node_modules/html-webpack-plugin/lib/loader.js' in '/app/perkoupon-main'
ModuleNotFoundError: Module not found: Error: Can't resolve '/app/perkoupon-main/node_modules/html-webpack-plugin/lib/loader.js' in '/app/perkoupon-main'
    at /app/perkoupon-main/node_modules/webpack/lib/Compilation.js:2084:28
    at /app/perkoupon-main/node_modules/webpack/lib/NormalModuleFactory.js:1060:13
    at eval (eval at create (/app/perkoupon-main/node_modules/tapable/lib/HookCodeFactory.js:31:10), <anonymous>:10:1)
    at /app/perkoupon-main/node_modules/webpack/lib/NormalModuleFactory.js:442:22
    at eval (eval at create (/app/perkoupon-main/node_modules/tapable/lib/HookCodeFactory.js:31:10), <anonymous>:9:1)
    at /app/perkoupon-main/node_modules/webpack/lib/NormalModuleFactory.js:628:22
    at /app/perkoupon-main/node_modules/webpack/lib/NormalModuleFactory.js:185:10
    at /app/perkoupon-main/node_modules/webpack/lib/NormalModuleFactory.js:864:23
    at /app/perkoupon-main/node_modules/webpack/lib/NormalModuleFactory.js:1370:5
    at /app/perkoupon-main/node_modules/neo-async/async.js:2830:7</pre>