Direct synchronisation problem

I am new to DevonThink Pro Office (version 2.8.2). Running OS X 10.10.1.

I have two macs connected through ethernet. I have successively set up a direct synchronisation (following the tutorial video: ‘Synchronizing databases between multiple Macs’).

However, when I disconnect one computer and then re-connect it, I can no longer synchronise. I get the following error message:

Even if I delete the existing connection and try to set up the connection as new I cannot do so as in the ‘Add Direct Connection’ box the ‘Server’ space is empty:

The computers (outside of Devon Think Pro Office) still communicate with each other (i.e. with Finder/Go/Connect to Server I connect from computer 1 to computer 2, or vice versa).

The only solution I have found is turn off both computers, reboot and then set up the connection again.

Is there any way that I can avoid having to do this, as I need to disconnect one of the computers several times a day (i.e. it is a laptop)?

This is likely an effect of the Yosemite sleep proxy bug that’s in early versions of Yosemite. IIRC you can get around this by disabling “wake over wifi” and then restarting your router.