Fatal error: Uncaught Error: Class 'craft\events\CancelableEvent' not found in /home/luxurytr/public_html/lt8/vendor/craftcms/cms/src/events/UserGroupsAssignEvent.php:16
Stack trace:
#0 {main}
thrown in /home/luxurytr/public_html/lt8/vendor/craftcms/cms/src/events/UserGroupsAssignEvent.php on line 16