I can't see any error messages. May you show which error messages are shown?

(In reply to comment #1)

I can't see any error messages. May you show which error messages are shown?

A database query syntax error has occurred. This may indicate a bug in the software. The last attempted database query was:

SELECT * FROM `protected_titles` WHERE pt_namespace = '-1' AND pt_title = 'Specialpages'

from within function "Database::select". MySQL returned error "1146: Table 'wiki.protected_titles' doesn't exist (localhost)".

Could that be the error message? In that case you have to run maintenance/update.php

I also don't get any errors, neither in 1.12svn nor in 1.11.0

OK, perhaps you can reproduce the following from my _offline_ _simulated_
Internet.

In LocalSettings.php use
$wgShowExceptionDetails = true;
$wgGroupPermissions['*']['read']=false;

Note the incorrect behavior with title=Special:Zzz,
and the correct behavior with title=Zzz, both of which do not exist.

$ w3m -dump http://transgender-taiwan.org/index.php?title=Special:Zzz\&uselang=en
[transgende]Internal error

Invalid special page name ""

Backtrace:

#0 /var/lib/mediawiki-1.11.0/includes/Title.php(1305): SpecialPage::getTitleFor
(false)
#1 /var/lib/mediawiki-1.11.0/includes/Wiki.php(133): Title->userCanRead()
#2 /var/lib/mediawiki-1.11.0/includes/Wiki.php(43): MediaWiki->
preliminaryChecks(Object(Title), Object(StubObject), Object(WebRequest))
#3 /var/lib/mediawiki-1.11.0/index.php(89): MediaWiki->initialize(Object
(Title), Object(StubObject), Object(User), Object(WebRequest))
#4 {main}

$ w3m -dump http://transgender-taiwan.org/index.php?title=Zzz\&uselang=en
Login Required ... You must log in to view other pages...

So we see requests for special pages that don't exist bypass some
checks, getting themselves into trouble.

What is worst is requests for special pages that _do_ exist.

$ w3m -dump http://transgender-taiwan.org/index.php?title=Special:Specialpages\&uselang=en

Warning: in_array() [function.in-array]: Wrong datatype for second argument in
/var/lib/mediawiki-1.11.0/includes/Title.php on line 1306

Login Required... You must log in to view other pages.

The error message jabs itself into the HTML...

Same error e.g., for Special:Listusers.

(Browser above doesn't send any cookies, but that doesn't matter.)
(The above is from a vanilla fresh install of 1.11. No need to run update.php.)

• This bug has been marked as a duplicate of bug 11668 ***