As noted in the logs for the cache where it was last dropped, it appears that your trackable has gone missing. I am moving your trackable to an "unknown location." (This option is also available to the cache owner and the owner of a travel bug or geocoin.) If it ever turns up again, the finder can grab it back without affecting the mileage. I am sorry that your trackable has stopped traveling.
Keystone
Geocaching.com Volunteer Cache Reviewer