To clarify:

I had 404 pages working for a while now. IIS and the Umbraco error page is created with the nodeId placed in the umbracoSettings.config file.

The issue is I just added a bunch of URL character replacements in the umbracoSettings.config file for Spanish, Czech, and French:

Character replacement

  <char org="ě">e</char>
  <char org="š">s</char>
  <char org="č">c</char>
  <char org="ř">r</char>
  <char org="ž">z</char>
  <char org="ý">y</char>
  <char org="á">a</char>
  <char org="í">i</char>
  <char org="é">e</char>
  <char org="ú">u</char>
  <char org="ů">u</char>
  <char org="ď">d</char>
  <char org="ť">t</char>
  <char org="ň">n</char>
  <char org="×">x</char>
  <char org="–">-</char>
  <char org="---">-</char>    

I had some titles of content nodes in Umbraco that had some of these accents in the URL. After republishing ALL content nodes that had these accents in the URL, I wanted to test to see if it worked.

Sure enough, the title still had the accent(s) in there, but the URL saved by Umbraco did not, which was the intended approach.

However, if lets say I had a content node,

• Title: Mí Page
• URL: /mí-page

Got turned into

• Title: Mí Page
• URL: /mi-page

And if I go to the newly created URL by Umbraco, the page displays. If I type in the first URL above, the page goes to a blank page, NOT the 404 page.

I see this in the console (the url is different, the above is just an example).

So this is indeed a 404, but going to a blank page now, not my 404 page. Has anybody else had this problem?