I put the OpenCore.efi and config.plist files in the ESP partition path /EFI/OC/ and add the line load fs0:\EFI\OC\OpenCore.efi to the VirtualBox EFI Internal Shell startup.nsh file.
error:fs0:\EFI\OC\OpenCore.efi is not a driver
opencore version:0.8.5
The load command is for drivers. Bootable .efi files are simply called by their full path and filename, for example fs0:\EFI\OC\OpenCore.efi (without load)
I put the OpenCore.efi and config.plist files in the ESP partition path /EFI/OC/ and add the line load fs0:\EFI\OC\OpenCore.efi to the VirtualBox EFI Internal Shell startup.nsh file.
error:fs0:\EFI\OC\OpenCore.efi is not a driver opencore version:0.8.5