Fatal error: Uncaught Error: Class "EntityReference_BehaviorHandler_Abstract" not found in /home/.sites/145/site372/web/sites/all/modules/entityreference/examples/entityreference_behavior_example/plugins/behavior/EntityReferenceFieldBehaviorExample.class.php:3
Stack trace:
#0 {main}
  thrown in /home/.sites/145/site372/web/sites/all/modules/entityreference/examples/entityreference_behavior_example/plugins/behavior/EntityReferenceFieldBehaviorExample.class.php on line 3