FATAL: No bootable medium found! system halted

Failed to open the disk image file D:macOS.Mojave.10.14.4macOS_10.14.4_Mojave.iso.

Could not get the storage format of the medium 'D:macOS.Mojave.10.14.4macOS_10.14.4_Mojave.iso' (VERR_NOT_SUPPORTED).

Result Code: VBOX_E_IPRT_ERROR (0x80BB0005)
Component: MediumWrap
Interface: IMedium {ad47ad09-787b-44ab-b343-a082a3f2dfb1}
Callee: IVirtualBox {d0a0163f-e254-4e5b-a1f2-011cf991c38d}
Callee RC: VBOX_E_OBJECT_NOT_FOUND (0x80BB0001)