It is fine on IE9

I've confirmed this on a Windows Vista (VM) with Internet Explorer 7 (logged out: http://en.wikipedia.org/wiki/Special:WhatLinksHere/Albert_Einstein )

Works fine on tests.wiki in the same environment:

http://test.wikipedia.org/wiki/Special:WhatLinksHere/Albert_Einstein

Might be a local javascript issue (doing a DOM operation that causes a loop or an illegal tree modification can cause IE7 to break the DOM entirely and display the error page)

Created attachment 10144
IE7 screen after closing the "Operation aborted" error

Looks like the resulting "Page could not be displayed" page is also fairly strongly cached afterwords. Refreshing doesn't give the alert again, it doesn't show the wiki at all.

Attached:

Looks like the initial page doesn't get aborted, only when submitted with an actual page title :

• fine: http://test.wikipedia.org/wiki/Special:WhatLinksHere/
• fine: http://test.wikipedia.org/wiki/Special:WhatLinksHere/Albert_Einstein
• fine: http://en.wikipedia.org/wiki/Special:WhatLinksHere/
• aborted: http://en.wikipedia.org/wiki/Special:WhatLinksHere/Albert_Einstein

does it also crash with debug=true, or with useskin=monobook ?

Yes, also fails with debug=true and useskin=monobook. This seems to be specific to the English Wikipedia, as other Wikipedias like Spanish and German work fine. So it must either be related to some local JS or an extension that is only running on en.wiki.

I bet it's related to whatever hack adds the link to dispenser's toolserver tool.

It was a self-closing span tag in http://en.wikipedia.org/wiki/MediaWiki:Linkshere