First off I am a huge fan of the Garmin inReach for safety while outside of cell phone range and other means of communication. I have one of the first inReach devices from before they were purchased from Delorme, and wrote a review of that device here.
Here is the email I received from Garmin today regarding the issue:
Issue with Posting to Facebook from inReach
We are currently experiencing a technical issue with the feature that enables inReach® users to post messages to a personal Facebook™ timeline. Most Facebook users will not be able to post to their personal timeline from their inReach device.
This system issue is due to recent changes Facebook implemented that change the way third-parties connect to Facebook accounts.
Posting from an inReach device to a Facebook page or a Twitter™ account is not impacted. This technical issue only relates to posting to a personal Facebook timeline.
Garmin is currently investigating possible solutions with Facebook; however, we may not be possible to restore this feature. We will continue to investigate a solution and will update inReach customers when this situation is resolved.
We apologize for the inconvenience. If you have questions, please contact the Garmin Support Center.