Fatal error: Uncaught Error: Class "yii\base\Behavior" not found in /home/telefonai/public_html/test.telefonai.eu/vendor/craftcms/cms/src/behaviors/FieldLayoutBehavior.php:28 Stack trace: #0 {main} thrown in /home/telefonai/public_html/test.telefonai.eu/vendor/craftcms/cms/src/behaviors/FieldLayoutBehavior.php on line 28