Go to Jukebox properties and find a field called available slots and define it as 1-96 (or 1-95 in case that slot 96 is reserved for cleaning slot).

It's there - perhaps you need to change into diagnostic view to see it.

I don't see that field. I only see Cleaning Slots. I'm using version 7.3.

After changing to diagnostic mode, I could see it. I changed Available Slots from 1-95, but it still shows 100 when doing the inventory.
I notice the Physical Slots 1 to 100 and it is grayed out, so I cannot change it.
Is there any way to fix this?

Thanks,

Only by doing jbconfig again. It means that you had 100 slots reported by library at the moment when original jbconfig was done.

Got the problem resolved.
Thanks for everyone's help.

I run jbconfig and this returns...

1) Configure an AlphaStor Library.
2) Configure an Autodetected SCSI Jukebox.
3) Configure an Autodetected NDMP SCSI Jukebox.
4) Configure an SJI Jukebox.
5) Configure an STL Silo.

What kind of Jukebox are you configuring? [1] 2
Scanning SCSI buses; this may take a while ...

All the Jukeboxes that are connected are already configured.
No new jukeboxes are found on host backup_server.

How do you run jbconfig again?

You will need to delete the library you have configured prior to running jbconfig. However, since it is detecting 100 slots it would be wise to check whether this is the correct value or that it has 96 slots as you believe.