Error when installing Ubuntu 20.04 64 bit (multiboot with Ubuntu 14.04 -64 bitand Windows 7) : Failed to register the EFI boot entry, operation not permitted

[rtnF]

Error when installing Ubuntu 20.04 64 bit (multiboot with Ubuntu 14.04 -64 bit and Windows 7) : Failed to register the EFI boot entry, operation not permitted

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity 20.04.15
ProcVersionSignature: Ubuntu 5.4.0-26.30-generic 5.4.30
Uname: Linux 5.4.0-26-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckMismatches: ./pool/restricted/l/linux-restricted-modules-oem-5.6/linux-modules-nvidia-440-5.6.0-1007-oem_5.6.0-1007.7_amd64.deb
CasperMD5CheckResult: skip
CasperVersion: 1.445
CurrentDesktop: ubuntu:GNOME
Date: Tue Jun 30 21:16:17 2020
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
ProcEnviron:
 LANGUAGE=en_US.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 LC_NUMERIC=C.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)