Airdrop between two MBPs only works in one direction - why? I have two 15" Retina MacBook Pros, a 2013 which is my work machine and a 2014 which is my personal machine. I'm trying to transfer some files between them using airdrop. Both have Yosemite on them and are on the same network. Both have been rebooted whilst on this network.

The 2014 MBP shows the 2013 MBP in airdrop and can drop files to it. In the 2013 MBP airdrop view, the 2014 MBP briefly appears whist the file is transferring and then disappears again.

The 2013 MBP does not see the 2014 MBP at all. Nor my iPhone either. And I cannot transfers files to the 2014 MBP. 

I completely flummoxed by this. The only difference I can see is the hardware. I've check firewall settings, sharing preferences, disk permissions and any thing else I can think of. But nothing seems to get the 2013 MBP to see the 2014 MBP.

I've also just noticed that the 2013 MBP cannot see any of the local shares. 

Any ideas whats wrong?

Thanks.
I found the answer. Something in the side bar preferences was messing with the system. I deleted this file from the 2013 MBP (which could not see the other machine or network drives):

~/Library/Preferences/com.apple.sidebarlists.plist


and rebooted. 

Then everything came back online and started working.