What's happening
Every time I use the nav menu on mobile tapping on any link whose target is neither on "Main" nor on "Category:" namespaces, the target link gets the following querry string:
?file=null&theme=undefined&mobile-app=false&comments_page=null&noexternals=undefined&uselang=undefined&from=null&debugAffiliateUnits=undefined&useskin=oasis
which ends up leading to the correct page, but with a popup over the page exactly like the one below:
X
Oops.
This item is no longer available, but now that you're here, explore the Community Central!
"Community Central" would be replaced by the name of the wiki, like when using the magic word {{SITENAME}}.
Tested
I've tested this on:
- devices:
- browsers:
- wikis:
- Community Central
example of menu link w/ error: News > Staff Blogs > Staff Blogs (namespace "Blog:")
- Fandom Developers Wiki
example of menu link w/ error: Content > Guides > JS & CSS cheatsheet (namespace "Help:")
- some other wikis
The error is the same in all these cases.
Details
If you're using a mobile device, but you've tapped the button "View full site" on the footer, which leads you to the desktop skin (URL ending with ?useskin=oasis), then the nav menu error won't happen. The error only happens if you access the nav menu on a mobile device AND on a page using the mobile skin (which is default for mobiles).
Example of namespaces that get the error: Blog, Board, Project, Help and Special.
Links to Special pages under the top option "Explore" (present in all wikis) do not generate the error, i.e.: the links "Wiki Activity", "Random page", "Community", "Videos", "Images", and "Forum", are OK.
But if admins add ANY special page (Special:RecentChanges, Special:AllPages, Special:ListFiles, etc.) to their nav menu through MediaWiki:Wiki-navigation, mobile users will get the error whenever they access those links.
About the querry string added to the link, I do not know what all those fragments are for; but the first part (?file=null
) is enough to generate the annoying popup.