Drivers must match calls to the routines that increase (reference) and decrease (dereference) the reference count. This bug check is caused by an inconsistency in the object's reference count. Typically, the inconsistency is caused by a driver that decreases the reference count of an object too many times, making extra calls that dereference the object. This bug check can occur because an object's reference count goes to zero while there are still open handles to the object. It might also occur when the object's reference count drops below zero, whether or not there are open handles to the object.