https://blogs.embarcadero.com/getit-update-rad-studio-12-getit-online-installation-is-now-available/   The new installer includes the Patch 1 fixes.    If you installed using the old online installer, you are unable to add platforms. If you need additional platforms, you will need to uninstall and reinstall using the new online installer (if you don't need additional platforms, you don't need to reinstall).   Patch 1 is available through GetIt, and is also available as a standalone installer from my.embarcadero.com for registered users.