Greetings. I have had the same issue for 3 weeks now. Previously set up syncs continue to work well, but I am not able to set up any new sync's to/from the freenas server because the GUI simply shows a grey box. Like the user who first reported the issue, I have tried the same troubleshooting actions, all in vain. Was about to give up and delete/fresh install btsync which would mean sync'ing the data all over again. But seeing this post gives me hope since others are facing the same problem as well.
