Im using DW 9, and are currently trying to setup a custom 404 page using the guide found here.
http://doc.dynamicweb.com/documentation-9/how-tos/install-setup/customizing-the-404-error-pages-on-your-solution
My setup
IIS:
https://www.screencast.com/t/gXMV35cnkMBQ
Apps -> Websites -> [Website]:
https://www.screencast.com/t/PVI9Xv6o1xS
The result
This actually works fine, but the problem is that I get a mix of both the standard DW error page and my custom error page on the same page.
https://www.screencast.com/t/daQIOHguXi
What am I doing wrong?