Fatal error: Uncaught Error: Class 'WP_Widget' not found in /home/.sites/8/site7281296/web/wp-content/plugins/jetpack/modules/widgets/milestone/class-milestone-widget.php:13
Stack trace:
#0 /home/.sites/8/site7281296/web/wp-content/plugins/jetpack/modules/widgets/milestone/milestone.php(11): require_once()
#1 /home/.sites/8/site7281296/web/wp-content/plugins/jetpack/modules/widgets/milestone.php(13): require_once('/home/.sites/8/...')
#2 {main}
  thrown in /home/.sites/8/site7281296/web/wp-content/plugins/jetpack/modules/widgets/milestone/class-milestone-widget.php on line 13