I installed the pearl theme 2.3x after installed and did the configuration after that I got this error I can't understand the issue please help me to fix this issue.
I using Cloudflare server and the os is Debian gnu Linux 9 and Magento version is 2.3
Issue
1 exception(s): Exception #0 (Magento\Framework\Config\Dom\ValidationException): Element 'font': This element is not expected. Expected is one of ( title, css, link, meta, script, remove, attribute ). Line: 1285
Element 'font': This element is not expected. Expected is one of ( title, css, link, meta, script, remove, attribute ). Line: 1293
Exception #0 (Magento\Framework\Config\Dom\ValidationException): Element 'font': This element is not expected. Expected is one of ( title, css, link, meta, script, remove, attribute ). Line: 1285
Element 'font': This element is not expected. Expected is one of ( title, css, link, meta, script, remove, attribute ). Line: 1293
#1 Magento\Framework\Config\Dom->__construct('createObject('Magento\Framewor...', array('create('Magento\Framewor...', array('xml' => ' '/mnt/data/home/2...', 'validationState' => &Magento\Framework\App\Arguments\ValidationState#000000003e5a6782000000001b0cec1a#)) called at [vendor/magento/framework/ObjectManager/ObjectManager.php:56] #4 Magento\Framework\ObjectManager\ObjectManager->create('Magento\Framewor...', array('xml' => ' '/mnt/data/home/2...', 'validationState' => &Magento\Framework\App\Arguments\ValidationState#000000003e5a6782000000001b0cec1a#)) called at [vendor/magento/framework/Config/DomFactory.php:43] #5 Magento\Framework\Config\DomFactory->createDom(array('xml' => ' '/mnt/data/home/2...', 'validationState' => &Magento\Framework\App\Arguments\ValidationState#000000003e5a6782000000001b0cec1a#)) called at [vendor/magento/framework/View/Model/Layout/Update/Validator.php:141] #6 Magento\Framework\View\Model\Layout\Update\Validator->isValid('_validateMergedLayout('LAYOUT_frontend_...', '\n load() called at [vendor/magento/framework/View/Layout/Builder.php:86] #9 Magento\Framework\View\Layout\Builder->loadLayoutUpdates() called at [vendor/magento/framework/View/Layout/Builder.php:63] #10 Magento\Framework\View\Layout\Builder->build() called at [vendor/magento/framework/View/Layout.php:253] #11 Magento\Framework\View\Layout->build() called at [vendor/magento/framework/View/Layout.php:875] #12 Magento\Framework\View\Layout->getBlock('page_content_hea...') called at [vendor/magento/module-cms/Helper/Page.php:171] #13 Magento\Cms\Helper\Page->prepareResultPage(&Magento\Cms\Controller\Index\Index\Interceptor#000000003e5a65a2000000001b0cec1a#, 'vaanyard-applied...') called at [vendor/magento/module-cms/Controller/Index/Index.php:74] #14 Magento\Cms\Controller\Index\Index->execute() called at [vendor/magento/framework/App/Action/Action.php:108] #15 Magento\Framework\App\Action\Action->dispatch(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#) called at [vendor/magento/framework/Interception/Interceptor.php:58] #16 Magento\Cms\Controller\Index\Index\Interceptor->___callParent('dispatch', array(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#)) called at [vendor/magento/framework/Interception/Interceptor.php:138] #17 Magento\Cms\Controller\Index\Index\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#) called at [vendor/magento/framework/Interception/Interceptor.php:153] #18 Magento\Cms\Controller\Index\Index\Interceptor->___callPlugins('dispatch', array(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#), array(array('designLoader', 'customerNotifica...', 'catalog_app_acti...', 'tax-app-action-d...', 'weee-app-action-...', 'storeCheck', 'contextPlugin', 'customer-app-act...'))) called at [generated/code/Magento/Cms/Controller/Index/Index/Interceptor.php:26] #19 Magento\Cms\Controller\Index\Index\Interceptor->dispatch(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#) called at [vendor/magento/framework/App/FrontController.php:159] #20 Magento\Framework\App\FrontController->processRequest(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#, &Magento\Cms\Controller\Index\Index\Interceptor#000000003e5a65a2000000001b0cec1a#) called at [vendor/magento/framework/App/FrontController.php:99] #21 Magento\Framework\App\FrontController->dispatch(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#) called at [vendor/magento/framework/Interception/Interceptor.php:58] #22 Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', array(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#)) called at [vendor/magento/framework/Interception/Interceptor.php:138] #23 Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#) called at [vendor/magento/module-store/App/FrontController/Plugin/RequestPreprocessor.php:94] #24 Magento\Store\App\FrontController\Plugin\RequestPreprocessor->aroundDispatch(&Magento\Framework\App\FrontController\Interceptor#000000003e5a662e000000001b0cec1a#, &Closure#000000003e5a67cd000000001b0cec1a#, &Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#) called at [vendor/magento/framework/Interception/Interceptor.php:135] #25 Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#) called at [vendor/magento/module-page-cache/Model/App/FrontController/BuiltinPlugin.php:73] #26 Magento\PageCache\Model\App\FrontController\BuiltinPlugin->aroundDispatch(&Magento\Framework\App\FrontController\Interceptor#000000003e5a662e000000001b0cec1a#, &Closure#000000003e5a67cd000000001b0cec1a#, &Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#) called at [vendor/magento/framework/Interception/Interceptor.php:135] #27 Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#) called at [vendor/magento/framework/Interception/Interceptor.php:153] #28 Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', array(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#), NULL) called at [generated/code/Magento/Framework/App/FrontController/Interceptor.php:26] #29 Magento\Framework\App\FrontController\Interceptor->dispatch(&Magento\Framework\App\Request\Http#000000003e5a66a0000000001b0cec1a#) called at [vendor/magento/framework/App/Http.php:137] #30 Magento\Framework\App\Http->launch() called at [vendor/magento/framework/App/Bootstrap.php:261] #31 Magento\Framework\App\Bootstrap->run(&Magento\Framework\App\Http\Interceptor#000000003e5a665f000000001b0cec1a#) called at [1010.php:39]
It seems like in one of your layout xml file header blocks, an illegal 'font' element is there.
Check your layout xml files. Specially header_default_block.xml files and basically all xml files for something like '<font'. If it is there, then remove it and see. May be you have to regenerate static content again.