Hi, I upgraded to Joomla 4. ALl components are updated and the backend runs without trouble. The site's front end runs on an Error 500. The debug suggests an issue withe the onepage Template:

at /var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/templates/shaper_onepage/error.php:103 at Joomla\CMS\Document\HtmlDocument->_loadTemplate() (/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/libraries/src/Document/HtmlDocument.php:796) at Joomla\CMS\Document\HtmlDocument->_fetchTemplate() (/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/libraries/src/Document/HtmlDocument.php:613) at Joomla\CMS\Document\HtmlDocument->parse() (/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/libraries/src/Document/HtmlDocument.php:631) at Joomla\CMS\Document\HtmlDocument->render() (/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/libraries/src/Document/ErrorDocument.php:139) at Joomla\CMS\Document\ErrorDocument->render() (/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/libraries/src/Error/Renderer/HtmlRenderer.php:78) at Joomla\CMS\Error\Renderer\HtmlRenderer->render() (/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/libraries/src/Exception/ExceptionHandler.php:121) at Joomla\CMS\Exception\ExceptionHandler::render() (/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/libraries/src/Exception/ExceptionHandler.php:72) at Joomla\CMS\Exception\ExceptionHandler::handleException() (/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/libraries/src/Application/CMSApplication.php:322) at Joomla\CMS\Application\CMSApplication->execute() (/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/includes/app.php:61) at require_once('/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/includes/app.php') (/var/www/vhosts/jochenvogt.www91.hostkraft.de/upgrade.gbs-abi84.de/index.php:32)

I tried all available PHP Versions 7.x and 8.x.

https://upgrade.gbs-abi84.de

Debug mode is on.

Could you please check?

Thanks, Jochen