I had this problem with Xubuntu 20.10 trying to install using KVM/QEMU but as it was only a VM i wiped it clean, tried formatting the partition with a gpt partition table and created both an EFI and a bios-boot partition but still no joy. I'm not sure if you can use gpt and UEFI within a KVM install, so that may be a "red herring"
I will try again today and ignore the error in the hope that grub has actually been installed.
Watch this space.
I had this problem with Xubuntu 20.10 trying to install using KVM/QEMU but as it was only a VM i wiped it clean, tried formatting the partition with a gpt partition table and created both an EFI and a bios-boot partition but still no joy. I'm not sure if you can use gpt and UEFI within a KVM install, so that may be a "red herring"
I will try again today and ignore the error in the hope that grub has actually been installed.
Watch this space.