MediaWiki internal error.

Original exception: exception 'MWException' with message 'Detected bug in an extension! Hook efGoogleAnalyticsHookText has invalid call signature; Parameter 1 to efGoogleAnalyticsHookText() expected to be a reference, value given' in /home/awikiventure/awikiventure.org/w/includes/Hooks.php:242
Stack trace:
#0 /home/awikiventure/awikiventure.org/w/includes/GlobalFunctions.php(3660): Hooks::run('SkinAfterBottom...', Array)
#1 /home/awikiventure/awikiventure.org/w/includes/Skin.php(717): wfRunHooks('SkinAfterBottom...', Array)
#2 /home/awikiventure/awikiventure.org/w/includes/SkinTemplate.php(451): Skin->bottomScripts(Object(OutputPage))
#3 /home/awikiventure/awikiventure.org/w/includes/OutputPage.php(1864): SkinTemplate->outputPage(Object(OutputPage))
#4 /home/awikiventure/awikiventure.org/w/includes/Wiki.php(396): OutputPage->output()
#5 /home/awikiventure/awikiventure.org/w/includes/Wiki.php(641): MediaWiki->finalCleanup()
#6 /home/awikiventure/awikiventure.org/w/includes/Wiki.php(547): MediaWiki->main()
#7 /home/awikiventure/awikiventure.org/w/index.php(57): MediaWiki->run()
#8 {main}

Exception caught inside exception handler: exception 'MWException' with message 'Detected bug in an extension! Hook efGoogleAnalyticsHookText has invalid call signature; Parameter 1 to efGoogleAnalyticsHookText() expected to be a reference, value given' in /home/awikiventure/awikiventure.org/w/includes/Hooks.php:242
Stack trace:
#0 /home/awikiventure/awikiventure.org/w/includes/GlobalFunctions.php(3660): Hooks::run('SkinAfterBottom...', Array)
#1 /home/awikiventure/awikiventure.org/w/includes/Skin.php(717): wfRunHooks('SkinAfterBottom...', Array)
#2 /home/awikiventure/awikiventure.org/w/includes/SkinTemplate.php(451): Skin->bottomScripts(Object(OutputPage))
#3 /home/awikiventure/awikiventure.org/w/includes/OutputPage.php(1864): SkinTemplate->outputPage(Object(OutputPage))
#4 /home/awikiventure/awikiventure.org/w/includes/Exception.php(183): OutputPage->output()
#5 /home/awikiventure/awikiventure.org/w/includes/Exception.php(209): MWException->reportHTML()
#6 /home/awikiventure/awikiventure.org/w/includes/Exception.php(392): MWException->report()
#7 /home/awikiventure/awikiventure.org/w/includes/Exception.php(471): MWExceptionHandler::report(Object(MWException))
#8 /home/awikiventure/awikiventure.org/w/includes/Wiki.php(550): MWExceptionHandler::handle(Object(MWException))
#9 /home/awikiventure/awikiventure.org/w/index.php(57): MediaWiki->run()
#10 {main}