npm run build fails - Githubissues

I get this error:
E:\DEV\jfxr\app>npm run build

> jfxr-app@0.9.1 build E:\DEV\jfxr\app
> grunt

Running "jshint:files" (jshint) task
>> 17 files lint free.

Running "webpack" task
Hash: 0490a0246d856f881d76
Version: webpack 4.22.0
Time: 85ms
Built at: 2018-10-21 20:53:08

ERROR in Entry module not found: Error: Can't resolve './app/js/index.js' in 'E:\DEV\jfxr\app'
Warning:  Use --force to continue.

Aborted due to warnings.
npm ERR! code ELIFECYCLE
npm ERR! errno 3
npm ERR! jfxr-app@0.9.1 build: `grunt`
npm ERR! Exit status 3
npm ERR!
npm ERR! Failed at the jfxr-app@0.9.1 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\blury\AppData\Roaming\npm-cache\_logs\2018-10-21T19_53_08_518Z-debug.log
ttencate / jfxr

npm run build fails #32
