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
wick editor’s downloadable apps are outdated (1.19.0 vs the main editor’s 1.19.3 or test editor’s 1.19.4) and not very stable. if you want a downloadable app, you can download the candlestick fork at https://github.com/Candlestickers/Candlestick/releases, which are mostly stable but still experimental. the most reliable version of the editor is the candlestick website, which dante already linked.