Hello Juergen,
Perhaps your computer temporarily lost the connection to the iLok dongle/Cloud. Please try:
- Reboot the computer.
- Make sure that the LED is lit within your iLok dongle, or that your iLok Cloud session is open on the computer (whichever is applicable) before launching Hauptwerk.
- Launch Hauptwerk and try loading the sample set again.
If that doesn't solve it, please use 'Help | Create a diagnostic file' and email the resulting file to Francois at support [at] hauptwerk.com , which hopefully will give some clue as to the cause of the problem. Thanks.