Board Thread:Support Requests - Getting Technical/@comment-32704847-20200425193029

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 !

Ok

"Community Central" would be replaced by the name of the wiki, like when using the magic word.

Tested
I've tested this on:
 * devices:
 * iphone 5S
 * iphone 6S
 * browsers:
 * Safari
 * Chrome
 * Brave
 * 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 is enough to generate the annoying popup.  