When writing to EEPROM for Modbus, KNX, Cbus, GSM4 and other UCM interfaces, if the message "Error Writing Configuration" appears..
This is probably due to a very old UCM firmware (UCM/USB or UCM/ETH03) for the UCM used to program the system. The old UCM firmware is not able to support new features in Comfort or Comfigurator, and thus needs to be upgraded
The UCM firmware should be upgraded to the latest, by right clicking on the UCM under Modules and selecting "Check for Firmware Upgrades"
You will be asked to press F0 on the keypad to enable Engineer Mode
If you see that message, please press F0 on the keypad. This is a protection against unauthorised upgrade.
This will allow the firmware upgrade to start