MediaWiki internal error.

Original exception: exception 'MWException' with message 'Unstub loop detected on call of $wgUser->isLoggedIn from LanguageConverter::getPreferredVariant
' in /usr/local/apache/common-local/php-1.5/includes/StubObject.php:68
Stack trace:
#0 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(45): StubObject->_unstub('isLoggedIn', 5)
#1 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(128): StubObject->_call('isLoggedIn', Array)
#2 [internal function]: StubUser->__call('isLoggedIn', Array)
#3 /usr/local/apache/common-local/php-1.5/languages/LanguageConverter.php(101): StubUser->isLoggedIn()
#4 /usr/local/apache/common-local/php-1.5/languages/LanguageSr.php(152): LanguageConverter->getPreferredVariant()
#5 /usr/local/apache/common-local/php-1.5/languages/Language.php(1180): SrConverter->getPreferredVariant(false)
#6 /usr/local/apache/common-local/php-1.5/includes/User.php(471): Language->getPreferredVariant(false)
#7 /usr/local/apache/common-local/php-1.5/includes/User.php(429): User->getDefaultOptions()
#8 /usr/local/apache/common-local/php-1.5/includes/User.php(129): User->loadDefaults()
#9 /usr/local/apache/common-local/php-1.5/includes/User.php(784): User->User()
#10 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(137): User->loadFromSession()
#11 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(71): StubUser->_newObject()
#12 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(45): StubObject->_unstub('isLoggedIn', 5)
#13 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(128): StubObject->_call('isLoggedIn', Array)
#14 [internal function]: StubUser->__call('isLoggedIn', Array)
#15 /usr/local/apache/common-local/php-1.5/languages/LanguageConverter.php(101): StubUser->isLoggedIn()
#16 /usr/local/apache/common-local/php-1.5/languages/LanguageSr.php(152): LanguageConverter->getPreferredVariant()
#17 /usr/local/apache/common-local/php-1.5/languages/Language.php(1180): SrConverter->getPreferredVariant(false)
#18 /usr/local/apache/common-local/php-1.5/includes/User.php(471): Language->getPreferredVariant(false)
#19 /usr/local/apache/common-local/php-1.5/includes/User.php(429): User->getDefaultOptions()
#20 /usr/local/apache/common-local/php-1.5/includes/User.php(129): User->loadDefaults()
#21 /usr/local/apache/common-local/php-1.5/includes/User.php(784): User->User()
#22 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(137): User->loadFromSession()
#23 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(71): StubUser->_newObject()
#24 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(45): StubObject->_unstub('isAllowed', 5)
#25 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(128): StubObject->_call('isAllowed', Array)
#26 [internal function]: StubUser->__call('isAllowed', Array)
#27 /usr/local/apache/common-local/php-1.5/includes/Title.php(1139): StubUser->isAllowed('read')
#28 /usr/local/apache/common-local/php-1.5/includes/Wiki.php(109): Title->userCanRead()
#29 /usr/local/apache/common-local/php-1.5/includes/Wiki.php(45): MediaWiki->preliminaryChecks(Object(Title), Object(StubObject), Object(WebRequest))
#30 /usr/local/apache/common-local/php-1.5/index.php(47): MediaWiki->initialize(Object(Title), Object(StubObject), Object(StubUser), Object(WebRequest))
#31 /usr/local/apache/common-local/live-1.5/index.php(3): require('/usr/local/apac...')
#32 {main}

Exception caught inside exception handler: exception 'MWException' with message 'Unstub loop detected on call of $wgUser->getOption from StubUserLang::_newObject
' in /usr/local/apache/common-local/php-1.5/includes/StubObject.php:68
Stack trace:
#0 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(45): StubObject->_unstub('getOption', 5)
#1 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(128): StubObject->_call('getOption', Array)
#2 [internal function]: StubUser->__call('getOption', Array)
#3 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(108): StubUser->getOption('language')
#4 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(71): StubUserLang->_newObject()
#5 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(45): StubObject->_unstub('getCode', 5)
#6 /usr/local/apache/common-local/php-1.5/includes/StubObject.php(101): StubObject->_call('getCode', Array)
#7 [internal function]: StubUserLang->__call('getCode', Array)
#8 /usr/local/apache/common-local/php-1.5/includes/MessageCache.php(423): StubUserLang->getCode()
#9 /usr/local/apache/common-local/php-1.5/includes/GlobalFunctions.php(450): MessageCache->get('internalerror', true, false)
#10 /usr/local/apache/common-local/php-1.5/includes/GlobalFunctions.php(409): wfMsgGetKey('internalerror', true, false, true)
#11 /usr/local/apache/common-local/php-1.5/includes/GlobalFunctions.php(316): wfMsgReal('internalerror', Array, true)
#12 /usr/local/apache/common-local/php-1.5/includes/Exception.php(37): wfMsg('internalerror')
#13 /usr/local/apache/common-local/php-1.5/includes/Exception.php(85): MWException->getPageTitle()
#14 /usr/local/apache/common-local/php-1.5/includes/Exception.php(56): MWException->htmlHeader()
#15 /usr/local/apache/common-local/php-1.5/includes/Exception.php(71): MWException->reportHTML()
#16 /usr/local/apache/common-local/php-1.5/includes/Exception.php(146): MWException->report()
#17 /usr/local/apache/common-local/php-1.5/includes/Exception.php(180): wfReportException(Object(MWException))
#18 [internal function]: wfExceptionHandler(Object(MWException))
#19 {main}