The procedure for building update clients for the opposite platform has changed in 4D v12. Reminder: an "update client" is a copy of the client that is used in the automatic update mechanism for clients via the network. With this feature a server can be deployed that includes an update client for both Mac OS X and Windows.
In 4D v12 the location of the "4D Volume Desktop" package of the opposite must be specified in the build settings, whereas in 4D v11 SQL the location of the actual merged client needed to be specified. For example:
4D v11 SQL
If you build the server on Windows, you need to first build the Mac OS X client on Mac OS X and then copy the client to Windows.
4D v12
If you build the server on Windows, you need only copy the "4D Volume Desktop.app" package from Mac OS X to Windows.
Note the description in the Build Application dialog has been changed: