| Error Message | Solution | |---------------|----------| | “Update failed – incompatible version” | Ensure base version is exactly 17.0 (not 17.0.1, not CS6). | | “Multilingual files missing” | Run the full installer package, not just the delta patch. Or reinstall base + full 17.1 updater. | | “Unable to launch because of missing language pack” | Go to C:\Program Files\Adobe\Adobe Illustrator CC 2014\Support Files\Contents\ and verify language subfolders (en_US, fr_FR, etc.). If missing, reapply the multilingual updater. | | “Error 1603 (Windows Installer)” | Clean install: Uninstall, use Adobe Cleaner Tool, reboot, then install base + update as admin. |