MediaWiki internal error.

Original exception: [b0eaa8c2b4d346e678bd4e0d] /w/index.php?title=Person:161115&action=history Error: Class "Wikibase\Repo\WikibaseRepo" not found
Backtrace:
from /var/www/html/extensions/WikibaseQualityConstraints/src/WikibaseQualityConstraintsHooks.php(108)
#0 /var/www/html/includes/HookContainer/HookContainer.php(159): WikibaseQuality\ConstraintReport\WikibaseQualityConstraintsHooks->onBeforePageDisplay(MediaWiki\Output\OutputPage, MediaWiki\Skins\Vector\SkinVector22)
#1 /var/www/html/includes/HookContainer/HookRunner.php(984): MediaWiki\HookContainer\HookContainer->run(string, array, array)
#2 /var/www/html/includes/Output/OutputPage.php(3186): MediaWiki\HookContainer\HookRunner->onBeforePageDisplay(MediaWiki\Output\OutputPage, MediaWiki\Skins\Vector\SkinVector22)
#3 /var/www/html/includes/actions/ActionEntryPoint.php(163): MediaWiki\Output\OutputPage->output(bool)
#4 /var/www/html/includes/MediaWikiEntryPoint.php(200): MediaWiki\Actions\ActionEntryPoint->execute()
#5 /var/www/html/index.php(58): MediaWiki\MediaWikiEntryPoint->run()
#6 {main}

Exception caught inside exception handler: [b0eaa8c2b4d346e678bd4e0d] /w/index.php?title=Person:161115&action=history Error: Class "Wikibase\Repo\WikibaseRepo" not found
Backtrace:
from /var/www/html/extensions/WikibaseQualityConstraints/src/WikibaseQualityConstraintsHooks.php(108)
#0 /var/www/html/includes/HookContainer/HookContainer.php(159): WikibaseQuality\ConstraintReport\WikibaseQualityConstraintsHooks->onBeforePageDisplay(MediaWiki\Output\OutputPage, MediaWiki\Skins\Vector\SkinVector22)
#1 /var/www/html/includes/HookContainer/HookRunner.php(984): MediaWiki\HookContainer\HookContainer->run(string, array, array)
#2 /var/www/html/includes/Output/OutputPage.php(3186): MediaWiki\HookContainer\HookRunner->onBeforePageDisplay(MediaWiki\Output\OutputPage, MediaWiki\Skins\Vector\SkinVector22)
#3 /var/www/html/includes/exception/MWExceptionRenderer.php(190): MediaWiki\Output\OutputPage->output()
#4 /var/www/html/includes/exception/MWExceptionRenderer.php(109): MWExceptionRenderer::reportHTML(Error)
#5 /var/www/html/includes/exception/MWExceptionHandler.php(133): MWExceptionRenderer::output(Error, int)
#6 /var/www/html/includes/exception/MWExceptionHandler.php(237): MWExceptionHandler::report(Error)
#7 /var/www/html/includes/MediaWikiEntryPoint.php(222): MWExceptionHandler::handleException(Error, string)
#8 /var/www/html/includes/actions/ActionEntryPoint.php(82): MediaWiki\MediaWikiEntryPoint->handleTopLevelError(Error)
#9 /var/www/html/includes/MediaWikiEntryPoint.php(206): MediaWiki\Actions\ActionEntryPoint->handleTopLevelError(Error)
#10 /var/www/html/index.php(58): MediaWiki\MediaWikiEntryPoint->run()
#11 {main}