Archicad 12 was released with a dedicated library that is distinct from newer versions. If you open a project created in AC12 within a modern version, or if you are working directly in AC12 and find that elements (doors, windows, furniture) are missing, you need the original library files.
: If your file relies on external links, missing library parts can corrupt the entire file hierarchy. Where to Find an Archicad 12 Library Download Archicad 12 Library Download
If you purchased Archicad 12 legally, your installation DVD or downloadable ISO image contains the library in its entirety. Archicad 12 was released with a dedicated library