What changed with the light service?

So I had until now without problem a automation running that was changing the rgb and brightness.

- service: light.turn_on
          brightness: 255
          - '0'
          - '255'
          - '0'
        entity_id: light.arbeitszimmer_tv_licht

But this does not work anymore. I wanted to debug and tried to setup the service in developer tools but only get strange error about

Fehler beim Aufrufen des Diensts light/turn_on. sequence item 0: expected str instance, Optional found

I am also unclear how to add the rob values there so I tried the color name thing and got the same error.

So changed something with the service? Can someone give a sample how it works for him?

This example:

    - service: light.turn_on
        entity_id: light.ledliststair
        brightness: 130
        rgb_color: [255,0,0]

was taken from https://www.home-assistant.io/integrations/light/
Hopefully it helps.

No idea what happened but without a change the automation works again. But still confused about the service tab in the developer tool