A 404 error is a standard response that indicates:
- A server is down.
- It cannot find the requested content (due to file or domain removal).
- The requested URL is broken.
Set one of your pages as a 404 page so that when a visitor tries to visit a page with the mentioned issues above, they will be redirected to your 404 page.
- Open the campaign
- Click Page Actions
- Select Make This My 404 (Error) Page
- Publish the page