SASS issue - no css generated with "ionic serve"


I have currently a weird issue with Ionic 2 on an Ubuntu droplet from Digital ocean.

I installed the latest version and all dependencies and, if I use “ionic build” everthing is generated fine - if I use “ionic serve” - it start the sass process, but it is never finished.

…the result, no valid css inside the www/build directory.

Here’s my current system information:

Your system information:

Cordova CLI: You have been opted out of telemetry. To change this, run: cordova telemetry on.

Ionic Framework Version: 2.0.0-rc.1
Ionic CLI Version: 2.1.4
Ionic App Lib Version: 2.1.2
Ionic App Scripts Version: 0.0.36
OS: Distributor ID:     Ubuntu Description:     Ubuntu 16.04.1 LTS
Node Version: v4.2.6

And this is the output, when I start “ionic serve”:

ionic-app-scripts watch

[14:43:54]  ionic-app-scripts 0.0.36
[14:43:54]  watch started ...
[14:43:54]  build dev started ...
[14:43:54]  clean started ...
[14:43:54]  clean finished in 11 ms
[14:43:54]  copy started ...
[14:43:54]  transpile started ...
[14:43:56]  lint started ...
[14:44:00]  lint finished in 4.47 s
[14:44:03]  transpile finished in 8.94 s
[14:44:03]  bundle started ...
[14:44:03]  copy finished in 9.04 s
[14:44:18]  bundle finished in 14.70 s
[14:44:18]  sass started ...
Running live reload server...

Does anyone have a glue, what’s going wrong and for which reason?