What does this message mean: 'Could not join the network'?

It could be that there is no response from our process "SyncingOlWatchService.exe". Maybe it is/was blocked by a Firewall/Antivirus program. Please allow the executable files 

- SyncService.exe
- SyncingOLWatchService.exe 
- NotificationService.exe 

access to the firewall settings. Then please close SYNCING.NET completely. Then please restart SYNCING.NET. 

If the error still occur, please reboot your system and try it again.