If the XING app doesn't work as expected, you should usually be able to fix that by:
- logging out and in again.
- reinstalling the app (uninstall it and download it again from Google Play).
If this doesn't help, please let us know about it via the XING contact form. Include in your message:
- which Android device you’re using
- which Android operation system version you're using
- which version of the app you’re using
You should inform us too whether or not your device has been rooted (if you don't know what this means, then your device will most probably not have been rooted ;-))