I got the issue while i add left sidebar in the style templateJoomla\CMS\WebAsset\Exception\UnknownAssetException:
There is no "template.cassiopeia.ltr" asset of a "preset" type in the registry.
at E:\xampp\htdocs\greek\libraries\src\WebAsset\WebAssetRegistry.php:134
at Joomla\CMS\WebAsset\WebAssetRegistry->get('preset', 'template.cassiopeia.ltr')
(E:\xampp\htdocs\greek\libraries\src\WebAsset\WebAssetManager.php:263)
at Joomla\CMS\WebAsset\WebAssetManager->useAsset('preset', 'template.cassiopeia.ltr')
(E:\xampp\htdocs\greek\libraries\src\WebAsset\WebAssetManager.php:197)
at Joomla\CMS\WebAsset\WebAssetManager->__call('usepreset', array('template.cassiopeia.ltr'))
(E:\xampp\htdocs\greek\templates\sparky_framework\error.php:58)
at require('E:\\xampp\\htdocs\\greek\\templates\\sparky_framework\\error.php')
(E:\xampp\htdocs\greek\libraries\src\Document\HtmlDocument.php:721)
at Joomla\CMS\Document\HtmlDocument->_loadTemplate('E:\\xampp\\htdocs\\greek\\templates/sparky_framework', 'error.php')
(E:\xampp\htdocs\greek\libraries\src\Document\HtmlDocument.php:776)
at Joomla\CMS\Document\HtmlDocument->_fetchTemplate(array('template' => 'flat', 'directory' => 'E:\\xampp\\htdocs\\greek\\templates', 'debug' => '1', 'csp_nonce' => null, 'templateInherits' => 'sparky_framework', 'params' => object(Registry), 'file' => 'error.php'))
(E:\xampp\htdocs\greek\libraries\src\Document\HtmlDocument.php:612)
at Joomla\CMS\Document\HtmlDocument->parse(array('template' => 'flat', 'directory' => 'E:\\xampp\\htdocs\\greek\\templates', 'debug' => '1', 'csp_nonce' => null, 'templateInherits' => 'sparky_framework', 'params' => object(Registry), 'file' => 'error.php'))
(E:\xampp\htdocs\greek\libraries\src\Document\HtmlDocument.php:630)
at Joomla\CMS\Document\HtmlDocument->render(false, array('template' => 'flat', 'directory' => 'E:\\xampp\\htdocs\\greek\\templates', 'debug' => '1', 'csp_nonce' => null, 'templateInherits' => 'sparky_framework', 'params' => object(Registry), 'file' => 'error.php'))
(E:\xampp\htdocs\greek\libraries\src\Document\ErrorDocument.php:139)
at Joomla\CMS\Document\ErrorDocument->render(false, array('template' => 'flat', 'directory' => 'E:\\xampp\\htdocs\\greek\\templates', 'debug' => '1', 'csp_nonce' => null, 'templateInherits' => 'sparky_framework', 'params' => object(Registry), 'file' => 'error.php'))
(E:\xampp\htdocs\greek\libraries\src\Error\Renderer\HtmlRenderer.php:78)
at Joomla\CMS\Error\Renderer\HtmlRenderer->render(object(Error))
(E:\xampp\htdocs\greek\libraries\src\Exception\ExceptionHandler.php:126)
at Joomla\CMS\Exception\ExceptionHandler::render(object(Error))
(E:\xampp\htdocs\greek\libraries\src\Exception\ExceptionHandler.php:72)
at Joomla\CMS\Exception\ExceptionHandler::handleException(object(Error))
(E:\xampp\htdocs\greek\libraries\src\Application\CMSApplication.php:322)
at Joomla\CMS\Application\CMSApplication->execute()
(E:\xampp\htdocs\greek\includes\app.php:61)
at require_once('E:\\xampp\\htdocs\\greek\\includes\\app.php')
(E:\xampp\htdocs\greek\index.php:32)
