Hi, start from that:

to see more details about error, it can be from old plugin or something else.

I did the actions and it gives me the following messages:

Function Location 1 () JROOT/plugins/arkmedia/search/search.php:56 2 plgArkMediaSearch->__construct() JROOT/libraries/src/Extension/ExtensionManagerTrait.php:242 3 Joomla\CMS\Application\CMSApplication->loadPluginFromFilesystem() JROOT/libraries/src/Extension/ExtensionManagerTrait.php:160 4 Joomla\CMS\Application\CMSApplication->loadExtension() JROOT/libraries/src/Extension/ExtensionManagerTrait.php:99 5 Joomla\CMS\Application\CMSApplication->bootPlugin() JROOT/libraries/src/Plugin/PluginHelper.php:232 6 Joomla\CMS\Plugin\PluginHelper::import() JROOT/libraries/src/Plugin/PluginHelper.php:192 7 Joomla\CMS\Plugin\PluginHelper::importPlugin() JROOT/administrator/components/com_arkmedia/helpers/ark.php:135 8 Ark\Media\Helper::add() JROOT/administrator/components/com_arkmedia/initiate.php:65 9 require_once() JROOT/plugins/quickicon/arkmedia/arkmedia.php:74 10 PlgQuickIconArkMedia->onGetIcons() JROOT/libraries/src/Plugin/CMSPlugin.php:284 11 Joomla\CMS\Plugin\CMSPlugin->Joomla\CMS\Plugin{closure}() JROOT/libraries/vendor/joomla/event/src/Dispatcher.php:486 12 Joomla\Event\Dispatcher->dispatch() JROOT/libraries/src/Application/EventAware.php:111 13 Joomla\CMS\Application\WebApplication->triggerEvent() JROOT/administrator/modules/mod_quickicon/src/Helper/QuickIconHelper.php:387 14 Joomla\Module\Quickicon\Administrator\Helper\QuickIconHelper->getButtons() JROOT/administrator/modules/mod_quickicon/src/Dispatcher/Dispatcher.php:38 15 Joomla\Module\Quickicon\Administrator\Dispatcher\Dispatcher->getLayoutData() JROOT/libraries/src/Dispatcher/AbstractModuleDispatcher.php:63 16 Joomla\CMS\Dispatcher\AbstractModuleDispatcher->dispatch() JROOT/libraries/src/Helper/ModuleHelper.php:281 17 Joomla\CMS\Helper\ModuleHelper::renderRawModule() JROOT/libraries/src/Helper/ModuleHelper.php:161 18 Joomla\CMS\Helper\ModuleHelper::renderModule() JROOT/administrator/components/com_cpanel/tmpl/cpanel/default.php:57 19 include() JROOT/libraries/src/MVC/View/HtmlView.php:410 20 Joomla\CMS\MVC\View\HtmlView->loadTemplate() JROOT/libraries/src/MVC/View/HtmlView.php:203 21 Joomla\CMS\MVC\View\HtmlView->display() JROOT/administrator/components/com_cpanel/src/View/Cpanel/HtmlView.php:158 22 Joomla\Component\Cpanel\Administrator\View\Cpanel\HtmlView->display() JROOT/libraries/src/MVC/Controller/BaseController.php:645 23 Joomla\CMS\MVC\Controller\BaseController->display() JROOT/administrator/components/com_cpanel/src/Controller/DisplayController.php:56 24 Joomla\Component\Cpanel\Administrator\Controller\DisplayController->display() JROOT/libraries/src/MVC/Controller/BaseController.php:678 25 Joomla\CMS\MVC\Controller\BaseController->execute() JROOT/libraries/src/Dispatcher/ComponentDispatcher.php:143 26 Joomla\CMS\Dispatcher\ComponentDispatcher->dispatch() JROOT/libraries/src/Component/ComponentHelper.php:361 27 Joomla\CMS\Component\ComponentHelper::renderComponent() JROOT/libraries/src/Application/AdministratorApplication.php:143 28 Joomla\CMS\Application\AdministratorApplication->dispatch() JROOT/libraries/src/Application/AdministratorApplication.php:186 29 Joomla\CMS\Application\AdministratorApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:293 30 Joomla\CMS\Application\CMSApplication->execute() JROOT/administrator/includes/app.php:61 31 require_once() JROOT/administrator/index.php:32

As you can see from first line, the PROBLEM is from Ark Media extension, both component and plugin:

/plugins/arkmedia/search/search.php

Disable them or uninstall (!) or install version for Joomla 4.x if exist. You have installed version for Joomla 3 only, not compatibile with new engine of Joomla 4.3. This is the main reason of error messages.

Our help ends here for obvious reasons, this is not our extension.

Thank you very much. Disable ark media and it works

I suggest to uninstall it completly, no signs of J4 version of that extension.

You're welcome