I want to create a network-wide 404 page, regardless of the template of the user's blog. All 404 errors should redirect to the custom 404 page.
According to my research on WP Codex, I need to create a 404 page for all themes. In my network, there are a lot of themes and I am searching a way to redirect all 404 errors to my custom 404 page (ex: my-site.com/404.php) without touching any template file.
How can it be possible?