Fatal error: Uncaught Error: Class 'yii\base\Behavior' not found in /home/mpolsk5/public_html/seocomo/craft/vendor/creocoder/yii2-nested-sets/src/NestedSetsBehavior.php:23
Stack trace:
#0 {main}
thrown in /home/mpolsk5/public_html/seocomo/craft/vendor/creocoder/yii2-nested-sets/src/NestedSetsBehavior.php on line 23