If virtual optical drives continue to fail, bypass the "unattended.iso" method by creating a bootable USB drive that includes your unattended settings.
If you absolutely need a third-party tool (because you must emulate a physical DVD drive with specific SCSI features), . The second better solution is replacing it with WinCDEmu (open-source) or Virtual CloneDrive (free for personal use).
Mount-DiskImage -ImagePath "C:\Path\To\Your\Unattended.iso"
If installing on hardware, use Rufus to create your bootable media.
18;write_to_target_document7;default0;a1;0;a1;18;write_to_target_document1a;_NzTuacLGJo3Ap84Ps52H4QM_20;a5;
Ensure your CD/DVD drive drivers are up-to-date. Outdated drivers can cause compatibility issues.