That’s an error most websites can have. It’s a broken image link or a broken image icon, its an asset loading error. To fix it you can reload the page.
As I can see, you’re using the desktop version, its kinda buggy so i’d recommend switching to the web version https://www.wickeditor.com/editor/. If you want the latest version you can try Candlestick, wick editor’s fork. https://candlestickers.app