GDS/KDS program cannot work properly on LTE/3G/4G tablet PC.
When you use GDS mobile/KDS on LTE/3G/4G tablet PC, even though you use mobile data for the internet connection, WiFi signal must be turned on your tablet PC.
1. Press and drag the main screen with your finger from top to bottom.
2. You can find WiFi button. Tab the WiFI button to activate.
3. Both wifi and mobile data must be on. Please check if those are activated as below.
4. Close the current windows and run GDS mobile/ KDS.
If it doesn't work, please contact firstname.lastname@example.org.