The extension is not the problem. It is mod. But when the mod is created with ArchiCAD 10 EDU, it is on the non-commercial format. When I open it with ArchiCAD 10 commercial, it can open PLN files, but not MOD files, for the reasons explained in my initial post.
I assume that the files can be read, but the switch from commercial to EDU (which occurs while opening EDU pln-files), is not working. With PLN files, when you open an EDU file, ArchiCAD switches to EDU mode but does not open the said file: you need to open it again. When ArchiCAD opens an EDU mod-file, it does not switch to EDU mode and does not open the file: you can try again, ad infinitum, but since you can't force the switch to EDU mode, the file can not be opened.
Stupid...
Maybe I can try to open the MOD file from ArchiCAD EDU and save it as a PLN file and open that in ArchiCAD commercial to export as MOD, but then I fear that the exported MOD file is back again an EDU file, which I can not open in the commercial version.
--- stefan boeykens --- bim-expert-architect-engineer-musician ---
Archicad28/Revit2024/Rhino8/Solibri/Zoom
MBP2023:14"M2MAX/Sequoia+Win11
Archicad-user since 1998
my Archicad Book