Custom element doesn't exist: hui-markdown-card - Huh?!

As the title says, I keep receiving an error when attempting to add an Custom Element to a picture-elements card…Admittedly I’m trying to hack some code together from some other examples I’ve found in the forum. Can someone shed some light as to what I’m going wrong?

My code:

  - type: picture-elements
    title: ''
    style: |
      ha-card { height: 120px !important; }
    image: /local/images/transp.png
      - type: state-label
        entity: sensor.waze_travel_time
        friendly-name: Commute -
          top: 15px
          left: 190px
      - type: custom:hui-markdown-card
        content: |
          left: 60%
          top: 90%

The markdown card is a core card in HA Lovelace, and as such cannot be added as an element to a picture-elements card.

The code you have copied was a hacky workaround that hasn’t worked reliably since at least version 0.107 if at all.

However, Thomas Lovén has developed a custom card that allows you to add core cards as elements or entity rows. It should achieve what you are aiming for, although I have no direct personal experience of using it in a picture-elements card, so can only go on what is said in the GitHub repository for the card.

If you give it a try, please report back if it works.