MediaWiki internal error.

Original exception: [5ef136d2] /index.php?title=Main_Page%7CMain Exception from line 192 of /home1/silver/public_html/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 /home1/silver/public_html/wiki/includes/Wiki.php(588): MediaWiki->performRequest()
#1 /home1/silver/public_html/wiki/includes/Wiki.php(447): MediaWiki->main()
#2 /home1/silver/public_html/wiki/index.php(46): MediaWiki->run()
#3 {main}

Exception caught inside exception handler: [543b3117] /index.php?title=Main_Page%7CMain Exception from line 222 of /home1/silver/public_html/wiki/includes/Hooks.php: Detected bug in an extension! Hook Cite::checkRefsNoReferences has invalid call signature; Parameter 2 to Cite::checkRefsNoReferences() expected to be a reference, value given
Backtrace:
#0 /home1/silver/public_html/wiki/includes/GlobalFunctions.php(4013): Hooks::run(string, array, NULL)
#1 /home1/silver/public_html/wiki/includes/parser/Parser.php(396): wfRunHooks(string, array)
#2 /home1/silver/public_html/wiki/includes/cache/MessageCache.php(1070): Parser->parse(string, Title, ParserOptions, boolean)
#3 /home1/silver/public_html/wiki/includes/Message.php(963): MessageCache->parse(string, Title, boolean, boolean, Language)
#4 /home1/silver/public_html/wiki/includes/Message.php(667): Message->parseText(string)
#5 /home1/silver/public_html/wiki/includes/Message.php(756): Message->toString()
#6 /home1/silver/public_html/wiki/includes/OutputPage.php(3654): Message->parseAsBlock()
#7 /home1/silver/public_html/wiki/includes/OutputPage.php(2203): OutputPage->addWikiMsgArray(string, array)
#8 /home1/silver/public_html/wiki/includes/exception/ErrorPageError.php(58): OutputPage->showErrorPage(Message, string, array)
#9 /home1/silver/public_html/wiki/includes/exception/BadTitleError.php(48): ErrorPageError->report()
#10 /home1/silver/public_html/wiki/includes/exception/MWExceptionHandler.php(44): BadTitleError->report()
#11 /home1/silver/public_html/wiki/includes/exception/MWExceptionHandler.php(139): MWExceptionHandler::report(BadTitleError)
#12 /home1/silver/public_html/wiki/includes/Wiki.php(454): MWExceptionHandler::handle(BadTitleError)
#13 /home1/silver/public_html/wiki/index.php(46): MediaWiki->run()
#14 {main}