Why is that when there is no existing RAID and the first inserted hard disk drive is removed, the RAID manager GUI cannot manage or connect to the RAID subsystem?

Question:

Why is that when there is no existing RAID and the first inserted hard disk drive is removed, the RAID manager GUI cannot manage or connect to the RAID subsystem?

Answer:

When hard disks are inserted in the disk slots, the first hard disk that is inserted is assigned “Port 0”.
Port 0 is the (in-band) channel that will be used by the RAID manager GUI to manage the RAID subsystem.
Other hard disks will be assigned Port1, Port 2, etc.
If the first hard disk assigned as Port 0 is removed, the RAID manager GUI cannot access and manage the RAID subsystem.
When a RAID is already created, the first hard disk that was inserted and assigned Port 0 (whether or not it is part of the RAID) can then be removed and the RAID manager GUI can still manage the RAID subsystem.