Hi Hermann,
It look like the dial plan and the Asterisk server are not the same version.
Please check both and make sure to upgrade/downgrade dial plan to the Asterisk server version.
1. Asterisk server version can be checked by clicking on the ‘Detect’ button at Preferences dialog.
2. Dial plan version can be upgraded/downgraded by selecting Dialplan -> Version … from the main menu.
I hope this helps.
Michael Denich
Apstel support team