Please open your project (e.g. 'HelloWorld') and select the profile brick within the Composer. Then have a look to the attribute 'PlatformPackage' within the Inspector. When you now open the drop-down list, you should see a couple of Win32 Platform Packages and a couple of STM32Fx Platform Packages, e.g. STM.STM32Fx.RGB565.
If the STM32Fx Platform Packages are missing, it seems that the STM32Fx Platform Package is not installed.