You download an updater (e.g., Flexi10.5.2_upd.exe ), but it says “Requires previous version” or “Key not found”.
The "password key upd" is not a magic bullet. It is a maintenance task. Treat your legacy software with respect, keep offline backups of your installer and password, and plan your migration to modern software within the next 12 months. flexisign pro 105 password key upd