Automation with alias 'set_heating_thermostat' could not be validated and has been disabled:?

Here’s what I meant when I suggested to adjust the quantity of thermostats based on whether it’s a holiday or not.

    - id: setHeatingThermostat
      alias: set_heating_thermostat
      description: Set all heating thermostats at midnight
      initial_state: true
      mode: single
      trigger:
        - platform: time
          at: "01:00:00"
      condition:
        - condition: state
          entity_id: input_boolean.heating_thermostat_enabled
          state: "on"
      action:
        - variables:
            base:
              - thermostat_office
              - thermostat_wc
              - thermostat_kitchen
              - thermostat_wohnzimmer1
              - thermostat_wohnzimmer2
              - thermostat_bad
              - thermostat_kinderzimmer1
              - thermostat_kinderzimmer2
            thermostats: >
              {{ base if is_state('input_boolean.holiday_enabled', 'on') 
                else base + ['thermostat_schlafzimmer', 'thermostat_fitnessraum'] }}
        - repeat:
            for_each: "{{ thermostats }}"
            sequence:
              - service: climate.set_temperature
                data:
                  temperature: >
                    {{ states('input_number.thermostat_summer') if is_state('sensor.thermostat_hc1_summer_mode', 'Sommer')
                      else states('input_number.' ~ repeat.item) }}
                target:
                  entity_id: "climate.{{ repeat.item }}"
              - delay:
                  milliseconds: 200