MediaWiki internal error.

Original exception: [73a73374ed28a1561478f42a] /index.php?title=Attribut:Dc:subject&oldid=1317&diff=prev Wikimedia\Assert\PostconditionException: Postcondition failed: makeTitleSafe() should always return a Title for the text returned by getRootText().
Backtrace:
from /var/www/mediawiki/vendor/wikimedia/assert/src/Assert.php(203)
#0 /var/www/mediawiki/includes/title/Title.php(2036): Wikimedia\Assert\Assert::postcondition()
#1 /var/www/mediawiki/skins/Vector/includes/FeatureManagement/Requirements/LimitedWidthContentRequirement.php(95): MediaWiki\Title\Title->getRootTitle()
#2 /var/www/mediawiki/skins/Vector/includes/FeatureManagement/Requirements/LimitedWidthContentRequirement.php(156): MediaWiki\Skins\Vector\FeatureManagement\Requirements\LimitedWidthContentRequirement::shouldDisableMaxWidth()
#3 /var/www/mediawiki/skins/Vector/includes/FeatureManagement/FeatureManager.php(161): MediaWiki\Skins\Vector\FeatureManagement\Requirements\LimitedWidthContentRequirement->isMet()
#4 /var/www/mediawiki/skins/Vector/includes/FeatureManagement/FeatureManager.php(141): MediaWiki\Skins\Vector\FeatureManagement\FeatureManager->isFeatureEnabled()
#5 [internal function]: MediaWiki\Skins\Vector\FeatureManagement\FeatureManager::MediaWiki\Skins\Vector\FeatureManagement\{closure}()
#6 /var/www/mediawiki/skins/Vector/includes/FeatureManagement/FeatureManager.php(142): array_map()
#7 /var/www/mediawiki/skins/Vector/includes/SkinVector22.php(218): MediaWiki\Skins\Vector\FeatureManagement\FeatureManager->getFeatureBodyClass()
#8 /var/www/mediawiki/includes/OutputPage.php(3375): MediaWiki\Skins\Vector\SkinVector22->getHtmlElementAttributes()
#9 /var/www/mediawiki/includes/skins/SkinMustache.php(67): OutputPage->headElement()
#10 /var/www/mediawiki/includes/skins/SkinTemplate.php(181): SkinMustache->generateHTML()
#11 /var/www/mediawiki/includes/OutputPage.php(2899): SkinTemplate->outputPage()
#12 /var/www/mediawiki/includes/MediaWiki.php(941): OutputPage->output()
#13 /var/www/mediawiki/includes/MediaWiki.php(576): MediaWiki->main()
#14 /var/www/mediawiki/index.php(50): MediaWiki->run()
#15 /var/www/mediawiki/index.php(46): wfIndexMain()
#16 {main}

Exception caught inside exception handler: [73a73374ed28a1561478f42a] /index.php?title=Attribut:Dc:subject&oldid=1317&diff=prev Wikimedia\Assert\PostconditionException: Postcondition failed: makeTitleSafe() should always return a Title for the text returned by getRootText().
Backtrace:
from /var/www/mediawiki/vendor/wikimedia/assert/src/Assert.php(203)
#0 /var/www/mediawiki/includes/title/Title.php(2036): Wikimedia\Assert\Assert::postcondition()
#1 /var/www/mediawiki/skins/Vector/includes/FeatureManagement/Requirements/LimitedWidthContentRequirement.php(95): MediaWiki\Title\Title->getRootTitle()
#2 /var/www/mediawiki/skins/Vector/includes/FeatureManagement/Requirements/LimitedWidthContentRequirement.php(156): MediaWiki\Skins\Vector\FeatureManagement\Requirements\LimitedWidthContentRequirement::shouldDisableMaxWidth()
#3 /var/www/mediawiki/skins/Vector/includes/FeatureManagement/FeatureManager.php(161): MediaWiki\Skins\Vector\FeatureManagement\Requirements\LimitedWidthContentRequirement->isMet()
#4 /var/www/mediawiki/skins/Vector/includes/FeatureManagement/FeatureManager.php(141): MediaWiki\Skins\Vector\FeatureManagement\FeatureManager->isFeatureEnabled()
#5 [internal function]: MediaWiki\Skins\Vector\FeatureManagement\FeatureManager::MediaWiki\Skins\Vector\FeatureManagement\{closure}()
#6 /var/www/mediawiki/skins/Vector/includes/FeatureManagement/FeatureManager.php(142): array_map()
#7 /var/www/mediawiki/skins/Vector/includes/SkinVector22.php(218): MediaWiki\Skins\Vector\FeatureManagement\FeatureManager->getFeatureBodyClass()
#8 /var/www/mediawiki/includes/OutputPage.php(3375): MediaWiki\Skins\Vector\SkinVector22->getHtmlElementAttributes()
#9 /var/www/mediawiki/includes/skins/SkinMustache.php(67): OutputPage->headElement()
#10 /var/www/mediawiki/includes/skins/SkinTemplate.php(181): SkinMustache->generateHTML()
#11 /var/www/mediawiki/includes/OutputPage.php(2899): SkinTemplate->outputPage()
#12 /var/www/mediawiki/includes/exception/MWExceptionRenderer.php(184): OutputPage->output()
#13 /var/www/mediawiki/includes/exception/MWExceptionRenderer.php(103): MWExceptionRenderer::reportHTML()
#14 /var/www/mediawiki/includes/exception/MWExceptionHandler.php(132): MWExceptionRenderer::output()
#15 /var/www/mediawiki/includes/exception/MWExceptionHandler.php(249): MWExceptionHandler::report()
#16 /var/www/mediawiki/includes/MediaWiki.php(595): MWExceptionHandler::handleException()
#17 /var/www/mediawiki/index.php(50): MediaWiki->run()
#18 /var/www/mediawiki/index.php(46): wfIndexMain()
#19 {main}