Fatal: No bootable medium found! System halted.

Problem description: fatal error. No media can be booted. The system is suspended.
The following is an online query:

1: Check whether the hard disk type, IDE or SATA interface is 0, 0, or 1, 0.

2: whether to select the ISO file for the optical drive.

3: whether the ISO file is damaged
4: virtualbox is started on a floppy disk by default. It is set to a CD (settings-system-startup sequence)
I encountered this error today.
Previously, virtual machines can be started normally, but I deleted a virtual disk. After adding a new virtual disk, I reported this error when I started the virtual machine.
Solution: Change the SATA port to 0.