MediaWiki internal error.

Original exception: exception 'DBQueryError' with message 'A database error has occurred. Did you forget to run maintenance/update.php after upgrading? See: https://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script
Query: SELECT page_id FROM `page` WHERE page_namespace = '6' AND page_title = 'Flag_of_Chile.svg' LIMIT 1
Function: LocalRepo::getArticleID
Error: 1047 WSREP has not yet prepared node for application use (192.168.42.42:3307)
' in /var/www/ISWiki/testing/releases/20200221115006/lib/includes/db/Database.php:918
Stack trace:
#0 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/db/Database.php(885): DatabaseBase->reportQueryError('WSREP has not y...', 1047, 'SELECT page_id...', 'LocalRepo::getA...', false)
#1 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/db/Database.php(1358): DatabaseBase->query('SELECT page_id...', 'LocalRepo::getA...')
#2 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/db/Database.php(1105): DatabaseBase->select('page', 'page_id', Array, 'LocalRepo::getA...', Array)
#3 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/filerepo/LocalRepo.php(206): DatabaseBase->selectField('page', 'page_id', Array, 'LocalRepo::getA...')
#4 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/filerepo/LocalRepo.php(163): LocalRepo->getArticleID(Object(Title))
#5 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/filerepo/RepoGroup.php(198): LocalRepo->checkRedirect(Object(Title))
#6 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/ImageFunctions.php(27): RepoGroup->checkRedirect(Object(Title))
#7 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/parser/Parser.php(1925): wfIsBadImage('Flag_of_Chile.s...', Object(Title))
#8 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/parser/Parser.php(1680): Parser->replaceInternalLinks2('?<div class="ta...')
#9 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/parser/Parser.php(1120): Parser->replaceInternalLinks('?<div class="ta...')
#10 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/parser/Parser.php(345): Parser->internalParse('{{CES Country?|...')
#11 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/WikiPage.php(2914): Parser->parse('{{CES Country?|...', Object(Title), Object(ParserOptions), true, true, 264218)
#12 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/PoolCounter.php(187): PoolWorkArticleView->doWork()
#13 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/WikiPage.php(862): PoolCounterWork->execute()
#14 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/diff/DifferenceEngine.php(523): WikiPage->getParserOutput(Object(ParserOptions), 264218)
#15 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/diff/DifferenceEngine.php(387): DifferenceEngine->renderNewRevision()
#16 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Article.php(682): DifferenceEngine->showDiffPage(false)
#17 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Article.php(434): Article->showDiffPage()
#18 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/actions/ViewAction.php(40): Article->view()
#19 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Wiki.php(484): ViewAction->show()
#20 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Wiki.php(278): MediaWiki->performAction(Object(Article))
#21 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Wiki.php(593): MediaWiki->performRequest()
#22 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Wiki.php(503): MediaWiki->main()
#23 /var/www/ISWiki/testing/releases/20200221115006/lib/index.php(58): MediaWiki->run()
#24 {main}

Exception caught inside exception handler: exception 'DBUnexpectedError' with message 'Error in numRows(): WSREP has not yet prepared node for application use (192.168.42.42:3307)' in /var/www/ISWiki/testing/releases/20200221115006/lib/includes/db/DatabaseMysql.php:234
Stack trace:
#0 /var/www/ISWiki/testing/releases/20200221115006/lib/extensions/SemanticForms/includes/SF_Utils.php(124): DatabaseMysql->numRows(false)
#1 /var/www/ISWiki/testing/releases/20200221115006/lib/extensions/SemanticForms/includes/SF_FormLinker.php(313): SFUtils::getCategoriesForPage(Object(Title))
#2 /var/www/ISWiki/testing/releases/20200221115006/lib/extensions/SemanticForms/includes/SF_FormEditAction.php(64): SFFormLinker::getDefaultFormsForPage(Object(Title))
#3 /var/www/ISWiki/testing/releases/20200221115006/lib/extensions/SemanticForms/includes/SF_FormEditAction.php(151): SFFormEditAction::displayTab(Object(SkinIswiki), Array)
#4 [internal function]: SFFormEditAction::displayTab2(Object(SkinIswiki), Array)
#5 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Hooks.php(216): call_user_func_array('SFFormEditActio...', Array)
#6 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/GlobalFunctions.php(3859): Hooks::run('SkinTemplateNav...', Array)
#7 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/SkinTemplate.php(981): wfRunHooks('SkinTemplateNav...', Array)
#8 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/SkinTemplate.php(455): SkinTemplate->buildContentNavigationUrls()
#9 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/OutputPage.php(1982): SkinTemplate->outputPage()
#10 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Exception.php(182): OutputPage->output()
#11 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Exception.php(209): MWException->reportHTML()
#12 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Exception.php(490): MWException->report()
#13 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Exception.php(569): MWExceptionHandler::report(Object(DBQueryError))
#14 /var/www/ISWiki/testing/releases/20200221115006/lib/includes/Wiki.php(506): MWExceptionHandler::handle(Object(DBQueryError))
#15 /var/www/ISWiki/testing/releases/20200221115006/lib/index.php(58): MediaWiki->run()
#16 {main}