virtualbox.org

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Progress state: VBOX_E_FILE_ERROR
VBoxManage: error: Appliance read failed
VBoxManage: error: Could not open the OVA file '/home/john/kali-linux-2018.1-vbox-amd64.ova' (VERR_FILE_NOT_FOUND)
VBoxManage: error: Details: code VBOX_E_FILE_ERROR (0x80bb0004), component ApplianceWrap, interface IAppliance
VBoxManage: error: Context: "RTEXITCODE handleImportAppliance(HandlerArg*)" at line 307 of file VBoxManageAppliance.cpp

I'm running Ubuntu 16.04, LTS 64 bit, 6GiB memory, Intel i5 cpu

I have a few other virtual machines that I've imported as ova files just fine.

Does the file exist? Can you read it (permissions)? Does it have a checksum that you can compare and make sure it's not corrupted?