I've never heard of that, do you have the problem if you restart your browser in safe/incognito mode?

It is not an Adobe Illustrator file,i t is a text file called "ai". I am also annoyed by this issue. Does anyone have any more information about this issue? 

I never heard about it and I never got one, so it's probably virus or error...

Is there anything inside that file? It might be an ad making the download, but that would most likely be a one-time issue. Try using another browser, clearing your cache, or sending a "DO NOT TRACK" request (google either of these for instructions). Can you answer these questions so that we can answer your question more accurately:

1. What browser are you using?
2. What page(s) does "ai" download on? All pages, just one wiki, just one page? If just one page or wiki, please give a link.
3. Does "ai" have an extension? Is it a .txt, a .html, no extension? (you might have to show file extensions, google "show file extensions" for instructions)
4. Does "ai" contain anything? If so, what?
5. Does "ai" download immediately after you load the page, or is there a slight delay?

This is happening to me too. Using Safari, it happens on a lot of pages (this one included). The file has no extension and when I try to open it, it just opens Preview on my Mac and shows a single white pixel. It downloads pretty much immediately for me, and it doesn't happen every time, but maybe every 4 or 5 pages or so.

It sounds like it does have an extension. If it didn't have an extension, it wouldn't open up in preview, because the Mac wouldn't know what to do with it. Here's how to check the file extension:

1. Open Terminal (click the magnifying glass in the top-right, type Terminal, click Terminal)
2. Type: defaults write com.apple.Finder AppleShowAllFiles TRUE
3. Type: killall Finder
4. Now check the file, it should say ai.xxx (the xxx being the file extension)
5. To turn it off, go to the terminal and type defaults write com.apple.Finder AppleShowAllFiles FALSE
6. Then killall Finder

Try checking the Javascript Console, do this by:

1. Typing command-comma (or go to Safari=>Preferences)
2. Under Advanced, check Show Develop Menu
3. Close the Preferences window
4. Under Develop, press Show Error Console
5. Refresh the page

Repeat the instructions but unchecking Show Develop Menu to hide it.

Hey, this was due to a misconfigured advertisement - rather than using a short snippet of text, it was downloading it as a file (if you opened it up in a text editor, it was a noticeably boring single line of text).

We believe the issue was resolved roughly two weeks ago. If you are continuing to see an issue, please send us a note at Special:Contact. Thanks!