I have installed D12 using the offline installer (ISO). 

The installer claimed to have installed Android NDK and SDK.

Under Tools / Options / Deployment / SDK Manager the paths for NDK & Java are marked as correct. But for the SDK all paths with the exception of "avdmanager.bat or android.bat location:" have an exclamation mark.

And indeed, C:\Users\Public\Documents\Embarcadero\Studio\23.0\CatalogRepository\AndroidSDK-2525-23.0.50491.5718 only contains the cmdline-tools subdirectory, and a couple of files (GetItInstall.dat, png, Eula, commandlinetools-win-9477386.zip).

On D11 the SDK directory is 1.4GB in size, and contains subdirectories "build-tools", "emulator", "platforms" etc etc.

So clearly the Delphi installer is not correctly/fully installing it.

Removing and re-adding it with "Manage Features..." results in the exact same result. No errors reported, but SDK is not fully installed.

Any pointers?