Last modified: 2014-08-16 19:35:44 UTC
If you go to your preferences, then the Sandbox link in the user panel at the top right hand side of the screen disappears and isn't there anymore. It reappears as soon as you leave your preferences.
Exposing "Sandbox" is en.wp specific and a gadget, see https://en.wikipedia.org/wiki/MediaWiki:Gadget-mySandbox.js https://en.wikipedia.org/wiki/Special:Gadgets/export/mySandbox https://en.wikipedia.org/wiki/Help:My_sandbox No idea why it's not shown on Preferences (wild guessing: security reasons?), but that's something to discuss on the Talk page of the gadget and not in Bugzilla :)
(In reply to Andre Klapper from comment #1) > No idea why it's not shown on Preferences (wild guessing: security > reasons?) Nope, that's it. User-authored scripts (gadgets, common.js, etc.) aren't allowed to run on Special:Preferences (and a few other pages) since they could steal private information.
Yay, I once was right. :P
This could be fixed if we actually did this in PHP rather than as a gadget, I filed a bug to do it: bug 69650.