Sound Designer II 2.82 was released prior to MacOS 8, and its copy protection is not fully MacOS 8 compatible. A work around would be to boot the Mac off OS 7.6.1 to install and authorize (or deauthorize) the Sound Designer II application onto the MacOS 8 drive. Once SDII is installed and authorized, it should be able to run under MacOS 8. An upgrade to Sound Designer II v2.8.3 with OS 8 compatible authorization disks is available from Digidesign Customer Service