Hello: I'm currently using Sync v1.2.92 There are 2 Windows 7 computers involved: A & B. A is behind a firewall and is on a static IP. B is also behind a firewall but is on DHCP-based ISP network. So I use A as the host. And B is primarily the back-up. It's supposed to connect to A and take a back-up whenever it switches itself on. And once in a while, if there's any activity on B, update A. On A, I have one folder shared. In "Properties" of that folder, everything is turned off except "Store deleted files in SyncArchive". On B, I have added that folder with the key. In "Properties" of that folder, everything is turned off except "Store deleted files in SyncArchive" and "Use predefined hosts" where I have provided the IP and port of A. I used a port check utility "https://www.grc.com/x/ne.dll?rh1dkyd2" to make sure outside world can see into A at the specified port. Now, when both machines are on, they don't sync. Sync on A even shows the IP of B in "Devices" but the Status is usually written as "U: 4.7 GB". Nothing else. The folders were sync'd once upon a time, using Sync, and the total diff is only of about 23 files worth about 25-30 MB. A few days ago, it just stopped happening. What's even more frustrating is that on random days, a few new files are sync'd -- there's no way of telling which ones would be, and when (at least I've not determined a pattern). Sync on B doesn't show A in the "Devices" list at all. The debug is enabled, but on both computers the log only shows "FFFF". There are a crazy amount of ping requests on sync.log on both computers. I even tried to enable "Use relay server when required", "Use tracker server", and even "Search DHT network" with no luck. All this resulted in was a lot more data in sync log about these services but no actual data to be transferred. Am I doing something wrong? Is there a problem with Sync? How can I fix this please? Thanks,