This isn’t really an error—when you embed a Haiku on the web, by default it has a right-click context menu that looks like this:
To populate the menu option, Haiku Core pings our server to see if the project was set to be “public” when it was published. The 404 just means it’s not public—and as a result, the right-click menu won’t show an option to “Fork this component” or “View on Haiku Community”.
If you want to disable the right-click menu in your app, you can set up your Haiku using the option
Here’s an example: https://codepen.io/anon/pen/PRpQVB