Older CD filesystems are unable to read these discs completely. To check your filesystem, open a shell and type
version CD0: full
replacing "CD0:" with the name of your CDROM drive. If you get a response of
cdfs.library 40.11 (09/11/1993)
you are using the old Commodore CD filesystem from the CD32 and OS 3.1. This This is almost certainly the worst CD filesystem ever invented. It's slow, buggy and doesn't support multi-session CDs.
The solution is to install AmiCDFS from a previous AACD, it's in AACD:AACD/Resources/CDROM/AmiCDFS2, or you can download the archive, complete with installer from here.