Customers need a means of accessing and converting old Archicad projects other than keeping an old computer running an old OS sitting around "just in case".
As is usual, Graphisoft only provides compatibility updates to the current and previous release of Archicad (two versions). This has worked fine in the past when all versions of Archicad could open old projects, however now we have a situation where only AC 26 and earlier can open projects from version 16 back to as old as version 8.1 ... and so if Archicad 26 cannot run, then those old projects are inaccessible with current Mac operating systems. See the macOS Sequoia KB article:
https://community.graphisoft.com/t5/Installation-update/macOS-15-Sequoia/ta-p/616173
and the file compatibility article:
https://community.graphisoft.com/t5/Licensing/Archicad-file-and-protection-compatibility/ta-p/304085
For many years, Graphisoft offered a special Archicad 10 "converter" version download that could open projects back to version 6.5 ... but that converter version is no longer compatible with macOS either. Thus, Mac users will very soon find themselves with no means of opening old projects, rendering their intellectual property inaccessible if those projects were never (tediously) migrated to a modern version.
This wish is for Graphisoft to maintain macOS compatibility for Archicad 26 indefinitely as a "converter version" for old projects... and/or to offer a compatible converter version similar to the old AC 10 converter.
PS. Even Archicad 28 can open files back to version 17 - so this wish only impacts users who have been customers for longer than 10 years.
Open