MQTT Light doesn't show up in UI

Hi,
I tried to add another MQTT Light to my homeassistant setup.
The problem is, it does not show up in the lovelace ui and I have no idea why.
my configuration.yaml contains:

light:
  - platform: mqtt
    name: "Jonas Lampe"
    state_topic: "jonas/light/status"
    command_topic: "jonas/light/switch"
    brightness_state_topic: 'jonas/light/brightness/status'
    brightness_command_topic: 'jonas/light/brightness/set'
    brightness_scale: 100
    rgb_state_topic: 'jonas/light/rgb/status'
    rgb_command_topic: 'jonas/light/rgb/set'
    qos: 0
    payload_on: "ON"
    payload_off: "OFF"
    optimistic: false
  - platform: mqtt
    name: "Jonas PCLight"
    state_topic: "jonas/pclight/status"
    command_topic: "jonas/pclight/switch"
    brightness_state_topic: 'jonas/pclight/brightness/status'
    brightness_command_topic: 'jonas/pclight/brightness/set'
    brightness_scale: 255
    rgb_state_topic: 'jonas/pclight/rgb/status'
    rgb_command_topic: 'jonas/pclight/rgb/set'
#    effect_state_topic: 'jonas/pclight/effect/status'
#    effect_command_topic: 'jonas/pclight/effect/set'
#    effect_list:
#      - Rainbow
#      - Flicker Blue
    qos: 0
    payload_on: "ON"
    payload_off: "OFF"
    optimistic: false

The first entry “Jonas Lampe” was already there and works well. I added the second entry
“Jonas PCLight” and then added this to my ui-lovelace.yaml:

  - title: Jonas
    cards:
      - type: light
        entity: light.jonas_lampe
        name: Lampe
      - type: light
        entity: light.jonas_pclight
        name: PC-Light

The new Tab in the lovelace UI appears as expected, but there is only one card that shows the entity: light.jonas_lampe, the new one, does not appear.

My log does not show a hint what the problem may be:

2019-11-12 22:00:29 ERROR (MainThread) [homeassistant.setup] Setup failed for introduction: Integration not found.
2019-11-12 22:00:31 WARNING (MainThread) [homeassistant.bootstrap] Python 3.6 support is deprecated and will be removed in the first release after December 15, 2019. Please upgrade Python to 3.7.0 or higher.
2019-11-12 22:00:32 WARNING (MainThread) [homeassistant.components.script] Script script.publish_mqtt_message already running.

Perhaps, someone has an idea, what the problem is?

It has to do with specifying the platform twice. Try this :

   - platform: mqtt
     name: "Jonas Lampe"
     state_topic: "jonas/light/status"
     command_topic: "jonas/light/switch"
     brightness_state_topic: 'jonas/light/brightness/status'
     brightness_command_topic: 'jonas/light/brightness/set'
     brightness_scale: 100
     rgb_state_topic: 'jonas/light/rgb/status'
     rgb_command_topic: 'jonas/light/rgb/set'
     qos: 0
     payload_on: "ON"
     payload_off: "OFF"
     optimistic: false

     name: "Jonas PCLight"
     state_topic: "jonas/pclight/status"
     command_topic: "jonas/pclight/switch"
     brightness_state_topic: 'jonas/pclight/brightness/status'
     brightness_command_topic: 'jonas/pclight/brightness/set'
     brightness_scale: 255
     rgb_state_topic: 'jonas/pclight/rgb/status'
     rgb_command_topic: 'jonas/pclight/rgb/set'

Sorry, TBH I was dumb AF.

My solution shown above does work but I edited my Backup file instead of the productive ones :grimacing:
And I was searching for so long, why it does not show up and also does not show an error message.