Check that Embedded library parts are saved with project to version 12!
LCF file with custom libraries is created in the same folder as archicad file for v 12.
Try then to load ArchiCAD pln file with standard libraries for AC 12 and this LCF file.
Why it is not working for version 14?!
Best
Rafał
//Archicad since 4.1 version
//MacBook Pro Retina 2019/2.4 GHz/Intel Core i9/32GB RAM/Radeon Pro 5500M 4GB/macOS 13.6
//Razer Intel i9/2.5GHz/32GB/Nvidia RTX 3080/Windows 11 Pro
//ArchiCAD 28/Twinmotion 2024