Warning: Error while sending QUERY packet. PID=2725846 in /var/lib/mediawiki/includes/libs/rdbms/database/DatabaseMysqli.php on line 46
MediaWiki internal error.

Original exception: [4de2580169e75358fc43f7a7] /index.php?title=Special:WhatLinksHere/E._Ozols&limit=250 Error from line 3133 of /var/lib/mediawiki/includes/parser/Parser.php: Call to a member function matchStartAndRemove() on null
Backtrace:
#0 /var/lib/mediawiki/includes/parser/Preprocessor_DOM.php(1279): Parser->braceSubstitution(array, PPFrame_DOM)
#1 /var/lib/mediawiki/includes/parser/Parser.php(3014): PPFrame_DOM->expand(DOMElement, integer)
#2 /var/lib/mediawiki/includes/parser/Parser.php(736): Parser->replaceVariables(string, PPFrame_DOM)
#3 /var/lib/mediawiki/includes/parser/Parser.php(4800): Parser->preprocess(string, Title, ParserOptions)
#4 /var/lib/mediawiki/includes/cache/MessageCache.php(1174): Parser->transformMsg(string, ParserOptions, Title)
#5 /var/lib/mediawiki/includes/Message.php(1282): MessageCache->transform(string, boolean, Language, NULL)
#6 /var/lib/mediawiki/includes/Message.php(883): Message->transformText(string)
#7 /var/lib/mediawiki/includes/Message.php(943): Message->toString(string)
#8 /var/lib/mediawiki/includes/exception/MWExceptionRenderer.php(205): Message->text()
#9 /var/lib/mediawiki/includes/exception/MWExceptionRenderer.php(144): MWExceptionRenderer::msg(string, string, string)
#10 /var/lib/mediawiki/includes/exception/MWExceptionRenderer.php(53): MWExceptionRenderer::reportHTML(Wikimedia\Rdbms\DBQueryError)
#11 /var/lib/mediawiki/includes/exception/MWExceptionHandler.php(98): MWExceptionRenderer::output(Wikimedia\Rdbms\DBQueryError, integer)
#12 /var/lib/mediawiki/includes/exception/MWExceptionHandler.php(172): MWExceptionHandler::report(Wikimedia\Rdbms\DBQueryError)
#13 /var/lib/mediawiki/includes/MediaWiki.php(544): MWExceptionHandler::handleException(Wikimedia\Rdbms\DBQueryError)
#14 /var/lib/mediawiki/index.php(46): MediaWiki->run()
#15 {main}

Exception caught inside exception handler: [4de2580169e75358fc43f7a7] /index.php?title=Special:WhatLinksHere/E._Ozols&limit=250 Wikimedia\Rdbms\DBConnectionError from line 1195 of /var/lib/mediawiki/includes/libs/rdbms/loadbalancer/LoadBalancer.php: Cannot access the database: Unknown error (localhost)
Backtrace:
#0 /var/lib/mediawiki/includes/libs/rdbms/loadbalancer/LoadBalancer.php(769): Wikimedia\Rdbms\LoadBalancer->reportConnectionError()
#1 /var/lib/mediawiki/includes/GlobalFunctions.php(2694): Wikimedia\Rdbms\LoadBalancer->getConnection(integer, array, boolean)
#2 /var/lib/mediawiki/includes/cache/LinkBatch.php(199): wfGetDB(integer)
#3 /var/lib/mediawiki/includes/cache/LinkBatch.php(141): LinkBatch->doQuery()
#4 /var/lib/mediawiki/includes/cache/LinkBatch.php(130): LinkBatch->executeInto(LinkCache)
#5 /var/lib/mediawiki/includes/skins/Skin.php(302): LinkBatch->execute()
#6 /var/lib/mediawiki/includes/skins/Skin.php(163): Skin->preloadExistence()
#7 /var/lib/mediawiki/skins/Timeless/includes/SkinTimeless.php(15): Skin->initPage(OutputPage)
#8 /var/lib/mediawiki/includes/skins/SkinTemplate.php(224): SkinTimeless->initPage(OutputPage)
#9 /var/lib/mediawiki/includes/OutputPage.php(2706): SkinTemplate->outputPage()
#10 /var/lib/mediawiki/includes/exception/MWExceptionRenderer.php(136): OutputPage->output()
#11 /var/lib/mediawiki/includes/exception/MWExceptionRenderer.php(53): MWExceptionRenderer::reportHTML(Error)
#12 /var/lib/mediawiki/includes/exception/MWExceptionHandler.php(98): MWExceptionRenderer::output(Error, integer)
#13 /var/lib/mediawiki/includes/exception/MWExceptionHandler.php(172): MWExceptionHandler::report(Error)
#14 /var/lib/mediawiki/includes/exception/MWExceptionHandler.php(144): MWExceptionHandler::handleException(Error)
#15 [internal function]: MWExceptionHandler::handleUncaughtException(Error)
#16 {main}