Default 404 page not working In a Drupal 8.5.3 installation I have set up the following configuration:


I created a basic page, its node path is /node/42.
Under Administration » Configuration » System » Basic site settings (/admin/config/system/site-information) I have set the Default 404 (not found) page to /node/42.


Now I expect a non-sensical URL to show the contents of /node/42 for the 404 page. However, I still only get the generic 404 page.

The theme we are using does not have a custom 404 template or anything like that. What other reasons could there be, that the default 404 page is not the one set in the config?
It was due to the multi-domain setup. I did not realize that you can/have to assign a different 404 page for each domain.