Appliance reimage via virtual media / virtual cdrom .iso fails "FileNotFoundError: [Errno 2] No such file or directory: '/dev/sr0'" / "Pane is dead"

Problem

Appliance reimage via virtual media (aka virtual cdrom) .iso fails with FileNotFoundError: [Errno 2] No such file or directory: '/dev/sr0'" /  "Pane is dead"
 

Error Message

Error in atexit._run_exitfuncs:
Traceback (most recent call last):
  File "/sbin/anaconda", line 90, in exitHandler
    if util.get_mount_paths(device_path):
  File "/usr/lib64/python3.6/site-packages/pyanaconda/core/util.py",
in get_mount_paths
     devno = os.stat(devnode).st_rdev
FileNotFoundError: [Errno 2] No such file or directory: '/dev/sr0'

Pane is dead (signal 7, <date>)

Example:

Cause

Network is unstable between appliance IPMI port and PC/laptop used to mount .iso virtual media
 

Solution

Due to the bandwidth required to install an ISO image through the IPMI network, the ISO installation works best if the appliance and the remote computer are located at the same physical site. If you try to remotely reimage an appliance over a WAN, the process can fail. Therefore, Veritas does not recommend performing an ISO reimage over a WAN. Rate limited VPN's can be just as problematic.

Alternatively, reimage via USB flash drive.
(Refer to the appropriate product guide for steps on reimaging using a USB drive). 
See following article on How to create a Flex Appliance USB flash drive