[SOLVED] Proxmox Migration Error: Can't use an undefined value as an ARRAY reference

[muaboka]

If you encounter the below error while trying to migrate a VM from with CLI or with GUI.

Error
Can't use an undefined value as an ARRAY reference at /usr/share/perl5/PVE/QemuServer.pm line 2579. (500)

Do check if you have an unreferenced USB device added to the VM. This is something I encountered and solved while fiddling around. So letting you all know.
BR,
MB