On my local wiki using sqlite. Checkout was from July 10 (9ff24c04f456)
[02385740b3221f7f4bc1275b] /w/load.php?debug=false&lang=en&modules=ext.CollaborationKit.hubtheme%7Cext.CollaborationKit.list.edit%2Cmembers%7Cext.eventLogging.subscriber%7Cjquery.accessKeyLabel%2CbyteLength%2CbyteLimit%2CcheckboxShiftClick%2Cclient%2Cconfirmable%2CfootHovzer%2CgetAttrs%2ChighlightText%2CmakeCollapsible%2Cmw-jump%2Cspinner%2Csuggestions%2CtabIndex%2CtextSelection%2Cthrottle-debounce%7Cmediawiki.ForeignApi%2CRegExp%2CTitle%2Capi%2Ccldr%2CconfirmCloseWindow%2Cdebug%2Chtmlform%2Cicon%2CjqueryMsg%2Clanguage%2Cnotify%2CsearchSuggest%2Cstorage%2Ctoolbar%2Cuser%2Cutil%2Cwidgets%7Cmediawiki.ForeignApi.core%7Cmediawiki.action.edit%7Cmediawiki.action.edit.collapsibleFooter%2CeditWarning%7Cmediawiki.api.edit%2Cuser%2Cwatch%7Cmediawiki.htmlform.ooui%7Cmediawiki.language.data%2Cinit%7Cmediawiki.libs.pluralruleparser%7Cmediawiki.page.ready%2Cstartup%7Cmediawiki.page.watch.ajax%7Cmediawiki.widgets.MediaSearch%2CUserInputWidget%2CvisibleByteLimit%7Coojs%2Coojs-ui%2Coojs-ui-core%2Coojs-ui-toolbars%2Coojs-ui-widgets%2Coojs-ui-windows%2Csite%7Coojs-ui.styles.icons-editing-advanced%2Cicons-moderation%2Cicons-movement%7Cskins.vector.js%7Cuser.defaults&skin=vector&version=18ccql8 Wikimedia\Rdbms\DBQueryError from line 1145 of /vagrant/mediawiki/includes/libs/rdbms/database/Database.php: A database query error has occurred. Did you forget to run your application's database schema updater after upgrading? Query: BEGIN Function: Wikimedia\Rdbms\Database::query (LinkCache::fetchPageRow) Error: 1 cannot start a transaction within a transaction Backtrace: #0 /vagrant/mediawiki/includes/libs/rdbms/database/Database.php(975): Wikimedia\Rdbms\Database->reportQueryError(string, integer, string, string, boolean) #1 /vagrant/mediawiki/includes/libs/rdbms/database/DatabaseSqlite.php(751): Wikimedia\Rdbms\Database->query(string, string) #2 /vagrant/mediawiki/includes/libs/rdbms/database/Database.php(2880): Wikimedia\Rdbms\DatabaseSqlite->doBegin(string) #3 /vagrant/mediawiki/includes/libs/rdbms/database/Database.php(914): Wikimedia\Rdbms\Database->begin(string, string) #4 /vagrant/mediawiki/includes/libs/rdbms/database/Database.php(1339): Wikimedia\Rdbms\Database->query(string, string) #5 /vagrant/mediawiki/includes/libs/rdbms/database/Database.php(1407): Wikimedia\Rdbms\Database->select(string, array, array, string, array, array) #6 /vagrant/mediawiki/includes/cache/LinkCache.php(313): Wikimedia\Rdbms\Database->selectRow(string, array, array, string) #7 /vagrant/mediawiki/includes/cache/LinkCache.php(270): LinkCache->fetchPageRow(Wikimedia\Rdbms\DatabaseSqlite, Title) #8 /vagrant/mediawiki/includes/Title.php(3255): LinkCache->addLinkObj(Title) #9 /vagrant/mediawiki/includes/Title.php(3272): Title->getArticleID(integer) #10 /vagrant/mediawiki/includes/resourceloader/ResourceLoaderWikiModule.php(156): Title->isRedirect() #11 /vagrant/mediawiki/includes/resourceloader/ResourceLoaderWikiModule.php(210): ResourceLoaderWikiModule->getContent(string) #12 /vagrant/mediawiki/includes/resourceloader/ResourceLoaderModule.php(644): ResourceLoaderWikiModule->getScript(ResourceLoaderContext) #13 /vagrant/mediawiki/includes/resourceloader/ResourceLoaderModule.php(612): ResourceLoaderModule->buildContent(ResourceLoaderContext) #14 /vagrant/mediawiki/includes/resourceloader/ResourceLoader.php(1051): ResourceLoaderModule->getModuleContent(ResourceLoaderContext) #15 /vagrant/mediawiki/includes/resourceloader/ResourceLoader.php(774): ResourceLoader->makeModuleResponse(ResourceLoaderContext, array, array) #16 /vagrant/mediawiki/load.php(53): ResourceLoader->respond(ResourceLoaderContext) #17 /var/www/w/load.php(5): include(string) #18 {main}