This is usually a result of network related processes.
Couple of things to try:
If you're on Windows:
1. Make sure that the AcaciaService.exe is added to the Windows firewall as an exception for both incoming and outgoing connections.
2. Make sure that the "Bonjour Service" is running according to 'services.msc'.
3. Restart the "Bonjour Service" via 'services.msc'.
If all else fails, restart your computer.