MediaWiki internal error.

Original exception: [bcfc8493] /wiki/index.php/Category:Symbian_C%252B%252B Exception from line 192 of /var/www/main/wiki/includes/Wiki.php: The requested page title was invalid, empty, or an incorrectly linked inter-language or inter-wiki title.
It may contain one or more characters that cannot be used in titles.
Backtrace:
#0 /var/www/main/wiki/includes/Wiki.php(588): MediaWiki->performRequest()
#1 /var/www/main/wiki/includes/Wiki.php(447): MediaWiki->main()
#2 /var/www/main/wiki/index.php(46): MediaWiki->run()
#3 {main}

Exception caught inside exception handler: [a340f5d7] /wiki/index.php/Category:Symbian_C%252B%252B Exception from line 222 of /var/www/main/wiki/includes/Hooks.php: Detected bug in an extension! Hook wfSetupImageMap has invalid call signature; Parameter 1 to wfSetupImageMap() expected to be a reference, value given
Backtrace:
#0 /var/www/main/wiki/includes/GlobalFunctions.php(4013): Hooks::run(string, array, NULL)
#1 /var/www/main/wiki/includes/parser/Parser.php(275): wfRunHooks(string, array)
#2 /var/www/main/wiki/includes/cache/MessageCache.php(1023): Parser->firstCallInit()
#3 /var/www/main/wiki/includes/cache/MessageCache.php(1000): MessageCache->getParser()
#4 /var/www/main/wiki/includes/Message.php(977): MessageCache->transform(string, boolean, Language, Title)
#5 /var/www/main/wiki/includes/Message.php(669): Message->transformText(string)
#6 /var/www/main/wiki/includes/Message.php(732): Message->toString()
#7 /var/www/main/wiki/includes/OutputPage.php(853): Message->text()
#8 /var/www/main/wiki/includes/OutputPage.php(898): OutputPage->setHTMLTitle(Message)
#9 /var/www/main/wiki/includes/OutputPage.php(2139): OutputPage->setPageTitle(string)
#10 /var/www/main/wiki/includes/OutputPage.php(2168): OutputPage->prepareErrorPage(Message)
#11 /var/www/main/wiki/includes/exception/ErrorPageError.php(58): OutputPage->showErrorPage(Message, string, array)
#12 /var/www/main/wiki/includes/exception/BadTitleError.php(48): ErrorPageError->report()
#13 /var/www/main/wiki/includes/exception/MWExceptionHandler.php(44): BadTitleError->report()
#14 /var/www/main/wiki/includes/exception/MWExceptionHandler.php(139): MWExceptionHandler::report(BadTitleError)
#15 /var/www/main/wiki/includes/Wiki.php(454): MWExceptionHandler::handle(BadTitleError)
#16 /var/www/main/wiki/index.php(46): MediaWiki->run()
#17 {main}