Homematic - variable not found

Hello,
when I tried to change system variable on CCU2 using homematic.set_variable_value service, but all I get is error variable xyz not found on ccu.

Here is my config:

homematic:
  interfaces:
    wired:
      host: 192.168.100.227
    rf:
      host: 192.168.100.227
  hosts:
    ccu2:
      host: 192.168.100.227

What am I doing wrong?

Hass.io version - 0.71
CCU2 firmware - 2.31.25

Thank you.

Try adding a username (default is Admin) and the corresponding password to the host-configuration. I’m not sure if it’s required, but if so, the documentation is misleading since it only says it’s needed to resolve names.