Ok, just in case, i'll describe my situation: I have PC A and PC B. I start by shutting down the client on PC B and create the shared folder on PC A, then untick ALL the options in "General" tab and leave only the "Predefined hosts" ticked and i fill in the correct host info and port to PC B. I then shut down PC A BTSync client. I now proceed to PC B and i'll add the new shared folder with the secret key i got from PC A. When the folder is ready, i untick ALL the options under "General" tab, as they are not needed there (correct me if i'm wrong, but i don't think PC B needs to connect to itself and all the other options are not needed as well, since i wwant to use predefined hosts). I save the settings and double-check if i have my PC B client listening on the correct port, yes it is. I now shut down the PC B BTSync client and start it up again. I now go to my PC A where i start up BTSync client and add some random mp3 files into the shared folder. PC A BTSync client successfully recognizes and indexes the files. I am now looking at PC B to see if these files sync to that and they DO NOT. Just in case i have both TCP AND UDP ports open in my router. I have double-checked to see if my router has UPnP enabled and as well as BTSync client. Port forwarding can't be the issue here, as i have other services running and i am accessible to the WAN. Which is weird though, is that when using a service like CanYouSeeMe(dot)org which checks for open ports, it says the port is closed on my BTSync client, should it say that? So can anyone else use the EXACT step-by-step guide to test if the predefined host method is working for them or not. Also to make sure NO OTHER shared folders are there in the "Shared Folders" list. It is also CRUCIALLY important to SHUT DOWN the other BTSync client, as if you test this on LAN or anywhere else and have the default options ticked, the clients exchange information and find themselves, so when you test with predefined hosts without shutting the clients down, they will see each other and the method "seems to be working" even though it is not (for me at least).