I have an iPhone 5s (iOS 7.1) and a MBP (Retina, late 2013) (Yosemite). I used to exchange files over Airdrop in both directions. Now sending files only works from the MBP to the iPhone. Sending from the iPhone automatically says declined by the MBP. (I don't even get the download prompt.)
Also, not sure this is relevant, but before the devices used to be able to see each other with the "Contacts only" setting. Now I have to set them both to "Everyone" for them to see each other.
What can be the problem? How can I debug this? I've restarted both devices, stopped Little Snitch, nothing changes.
Found this message in the Console app:
AirDrop failed to validate Apple ID certificate of sender
So I signed out and back to Apple ID on the phone and reset the network settings, still doesn't work.