Start the DHCP-Redundancy config utility and stop the service in the menu.
Click advanced settings and enable debug, save the settings.
Start the service again from the menu.
Wait two minutes, stop the main dhcp service, wait two minutes after the second DHCP service is up, start the main DHCP service again and again wait two minutes.
Disable debugging with the config utility.
In the installation directory there is now a file named debug.txt, please mail it to me.