Still exists in 5.0.1 (791) - for testing after the fix:

• Search for 'Special:' will display a full suggestions list
• from the suggested results clicking on any article name will display a blank page with a warning 'page doesn't exist'
• the Save button is active and the article (not displayed) can be "saved"
• "Saved" Special pages are displayed with full titles in Saved/History
• "Viewing" Special articles triggers 'Because you read' suggestions which are displayed as empty placeholders

@MBinder_WMF can you link this up with the Namespace epic? Thanks.

Lets try to see if there is a very quick fix for in app, otherwise lets push to mobile web for these pages.

I've been debugging this issue for a while. These are my findings for the next person that put some time on it:

1. The API Request is made correctly, the page parameter is sent, however the API response is erroneous:

In WMFArticleViewController the method

- (void)fetchArticleForce:(BOOL)force

Receives the error "missingtitle"

2. The mobile web version is retrieving the page properly, you could check with them :
   
   a) Are they using the same API with the same paremeters to retrieve special pages?
   
   b) If not, how is the web mobile version retrieving special pages?.
   
   Search for Special pages on the web mobile version here: Web Mobile Version

3. Paste the request on the browser to see the response + error quickly:

[[ https://en.m.wikipedia.org/w/api.php?action=mobileview&format=json&noheadings=true&page=Special%3AActiveUsers&prop=sections%7Ctext%7Clastmodified%7Clastmodifiedby%7Clanguagecount%7Cid%7Cprotection%7Ceditable%7Cdisplaytitle%7Cthumb%7Cdescription%7Cimage%7Crevision&sectionprop=toclevel%7Cline%7Canchor%7Clevel%7Cnumber%7Cfromtitle%7Cindex&sections=all&thumbwidth=640

Error response:

{"servedby":"mw1194","error":{"code":"missingtitle","info":"The page you requested doesn't exist","*":"See https://en.wikipedia.org/w/api.php for API usage"}}

4. For quick fix: if the search title text begins with "Special:" redirect to mobile browser i.e **https://en.m.wikipedia.org/wiki/Special:AllMyUploads**

Error screen should be standard "Could not load article" screen.

Error banner should be "The page you requested cannot be opened. Tap to open in Safari." and (nice-to-have) should tap through to Safari with URL loaded.