This is a minor bug in FMP 16 on both macOS El Capitan and macOS Sierra. Not a huge deal, but thought you should know.
We have a launcher file that users put in their dock. This is a .fmp12 file that automatically opens the remote file on the FMP 15 Server. It simply opens the file at this external path: fmnet:/IP_Address/File_Name
Launcher file works fine with FMP 15. However, upon upgrading the client machines to FMP 16, the launcher file says that the remote file cannot be found. So, for some reason, the launcher file isn't able to resolve the external path at fmnet:/IP_Address/File_Name
The workaround for this is for each client machine to manually open the external file by choosing "File > Open Remote..." one time only.
Once they successfully open the file via "Open Remote..." just once, then the launcher file automatically & immediately starts working from that point onward.