Hello Carsten,
We have build a network reset into the CueCore. If you press and hold the reset button for more then 3 seconds the CueCore should change it's IP address to 192. 168. 1. 10. At this point connecting a computer with the IP address 192. 168. 1. 9 directly to the CueCore should allow you access to the unit.
If this does not help you I will need more information about you setup.
1. How have you connected the CueCore to you computer?
2. Is there a router in your network?
3. What is the IP address of the computer you are using?
4. Are you using a CueCore or a CueCore2.
5. Are you using a computer with multiple networks. ( Cabled and WIFI )
Best regards,
Guido