Warning: Uncaught TYPO3\CMS\Core\Error\Exception: PHP Warning: require_once(PATH_tslibclass.TYPO3\CMS\Frontend\Plugin\AbstractPlugin.php): failed to open stream: No such file or directory in /var/www/vhosts/ski-wagrain.at/httpdocs/typo3conf/ext/weeaar_googlesitemap/pi1/class.tx_weeaargooglesitemap_pi1.php line 33 in /var/www/vhosts/ski-wagrain.at/httpdocs/typo3_src-8.7.29/typo3/sysext/core/Classes/Error/ErrorHandler.php:107 Stack trace: #0 /var/www/vhosts/ski-wagrain.at/httpdocs/typo3conf/ext/weeaar_googlesitemap/pi1/class.tx_weeaargooglesitemap_pi1.php(33): TYPO3\CMS\Core\Error\ErrorHandler->handleError(2, 'require_once(PA...', '/var/www/vhosts...', 33, Array) #1 /var/www/vhosts/ski-wagrain.at/httpdocs/typo3conf/ext/weeaar_googlesitemap/pi1/class.tx_weeaargooglesitemap_pi1.php(33): require_once() #2 /var/www/vhosts/ski-wagrain.at/httpdocs/typo3_src-8.7.29/vendor/composer/ClassLoader.php(444): include('/var/www/vhosts...') #3 /var/www/vhosts/ski-wagrain.at/httpdocs/typo3_src-8.7.29/vendor/composer/ClassLoader.php(322) in /var/www/vhosts/ski-wagrain.at/httpdocs/typo3_src-8.7.29/typo3/sysext/core/Classes/Error/ErrorHandler.php on line 107

Fatal error: main(): Failed opening required 'PATH_tslibclass.TYPO3\CMS\Frontend\Plugin\AbstractPlugin.php' (include_path='.:/opt/plesk/php/7.1/share/pear') in /var/www/vhosts/ski-wagrain.at/httpdocs/typo3conf/ext/weeaar_googlesitemap/pi1/class.tx_weeaargooglesitemap_pi1.php on line 33