We've introduced custom 404 error pages to give you greater control over the customer experience on your ecommerce site.
Custom error pages allow you to maintain your brand consistently across your entire site, including during error scenarios. This creates a more professional and trustworthy impression for your customers, even when something goes wrong. Additionally, well-designed error pages can offer clear navigation options to help customers stay engaged and reduce bounce rates. From an SEO perspective, custom 404 pages can include helpful content and internal links, which improve crawlability and minimize the negative impact of broken or outdated URLs.
Customising the error page in Cloud MT
1) By default, your 404 Error page will contain the following content, in your default font:

2) To change this, login to Cloud MT and open the main menu. Click on Content Management, then click on Not Found (404) Page.

3) You can change the title, and decide on the content you want to include. You can also add a background image. When you're happy, click Save at the bottom right.

4) You can preview the changes you've made using this link at the top (you'll need to have clicked the Save button for them to pull through):

5) You can use basic HTML to tweak and customise the page content to your heart's content, or you can keep it quite simple – whatever feels the most consistent for your brand. You can also change which page the "Return to homepage" button links to (at which point, you'd probably want to change what it says as well!).
This page will show any time that the site brings up a 404 error, including any redirects that you have set up to return a 404 Not Found response. For more information on using redirects, have a read of the Redirect Manager How To Guide.