V-Emoji-Picker | customizable package of Emoji Picker | Icon library

It could be that some dependency of yours is using ES6 syntax.

By default babel-loader ignores all files inside node_modules. If you want to explicitly transpile a dependency with Babel, you can list it in this option

transpileDependencies

You need to find out which one it is and add it to transpileDependencies - vue.config.js

Also the error message is very strange - function(e){let{existsSync:r,readFileSync:i} - both existsSync and readFileSync look like Node API. So check you don't use any Node package for browser app (for example node-fetch is definitely Node only lib and will not work inside the browser)