This screen brought to you by upgrading from 84.2 to 84.3. No errors logged anywhere.
That one won’t get past the configuration check. I must be putting it in the wrong place. Here’s what I have in my configuration.yaml:
panel_iframe:
windy:
title: Radar
icon: mdi:weather-cloudy
url: http://www.windy.com/-Radar-lightning-radar?radar,29.621,-97.622,8
ide:
title: IDE
icon: mdi:code-braces
url: http://192.168.1.181:8321
IDE works just fine. Radar did until upgrade this morning. There were no other changes made.
Apologies I am using mine as a lovelace iframe card - different to what you are doing.