Vertical stack suddenly showing an error although working fine in frontend

I have a vertical stack that was working fine last week but is now showing an error when trying to edit it, even if I remove both cards.

I also noticed that when adding a new vertical stack and cancelling without actually creating it, I can edit the existing one again until the next reload.

Is this a known issue?

type: custom:vertical-stack-in-card
cards:
  - type: custom:weather-card
    entity: weather.home_assistant
    details: false
    forecast: false
    card_mod:
      style: |
        ha-card {
          padding-bottom: 0px !important;
        }
  - type: custom:hourly-weather
    entity: weather.home_assistant
    icons: true
    show_precipitation_amounts: false
    show_precipitation_probability: true
    num_segments: "9"
    name: " "
    card_mod:
      style: |
        ha-card {
          border: none;
          margin-top: -15px;
        }

Hello,

I have seen the same yesterday.
A reboot solved the issue.
Is probably something going wrong in config did not found yet the cause, maybe just something going wrong with the custom vertical stack.

Try to replace inner cards with something simple and stock like Entity card and retest.

Like I said, even without entries it gives me an error.

type: custom:vertical-stack-in-card
cards: []

Ask in the card’s repo, probably create an issue.