I have FMS 16 and am successfully connected to it with FMGo 16. There are several DBs on this single host and all but one run on Go without any issue. But one wants to be difficult and is giving the error "The file could not be opened. (Not Found)." The file/db opens just fine in FMPro 16.
Development of this particular solution is just beginning. At this point, it has one table, one record, one layout and zero scripts. It does have user security setup with two user accounts ... Admin and my account. Both are password protected.