As of QAS 4.2 Solaris 8 is no longer supported, the supported platforms for QAS 4.2 can be found here:
https://support.oneidentity.com/technical-documents/authentication-services/4.2.2/release-notes/2#TOPIC-1325380
QAS 4.1.8 is the last version with support for Solaris 8 systems, that version can be found here:
https://support.oneidentity.com/kb/228689