Yesterday Embarcadero released a patch for the 12.1 version of RAD Studio. You can read more information on the official announcement blog post at https://blogs.embarcadero.com/rad-studio-12-1-athens-patch-1-available/
The focus is the Delphi 64bit compiler (only in the context of building packages), editor split views (a new, very nice feature in 12.1) and the debugger for non Windows platforms. The new patch is advertized in the Welcome page and can be installed via GetIt:
If you click install, you'll ahve toa ccept the EULA and close the IDE to get the patch installed:
As the IDE shuts down, it starts a command line window (and waits for you to accept the UAC prompt from Windows), it downlaods the actual patch, and installs it from the command line:
Now restart the IDE and in the about box, you can see that the patch is installed:
The alternative option is to download and install manually. Third party component vendors, please read the Win64 packages note in the readme (also in the blog post linked above), it's important!