When running the webpack-dev-server; it hits the exception "Unexpected token ILLEGAL"

...
   [71] (webpack)-dev-server/~/sockjs-client/lib/facade.js 723 bytes {0} [built]
   [72] (webpack)-dev-server/~/strip-ansi/index.js 161 bytes {0} [built]
   [73] (webpack)-dev-server/~/strip-ansi/~/ansi-regex/index.js 135 bytes {0} [built]
   [74] (webpack)/hot/dev-server.js 1.85 kB {0} [built]
   [75] (webpack)/hot/log-apply-result.js 813 bytes {0} [built]

ERROR in /Users/leow/OTTO/WORKSPACE/vue-hackernews/node_modules/babel-core/node_modules/lodash/object/keysIn.js:55
  for (var key in object

Unexpected token ILLEGAL
 @ multi main
webpack: bundle is now VALID.

Any clue why?