Multi boot system but no Grub Menu

[1fallen]

You don't load it to a USB drive, Gnome Disks will install it to your USB drive though

I assume you unziped it, and inside that Folder you will see a ".img"
ie:

cd /home/me/Downloads/refind-flashdrive-0.12.0/ && ls
COPYING.txt  LICENSE.txt  README-flashdrive.txt         SHELLS.txt
CREDITS.txt  NEWS.txt     refind-flashdrive-0.12.0.img

Point that with Gnome Disks and in the top right hand corner you see 3 vertical Dots Select Restore Disk Img

I'm sorry I'm so assuming, it's hard for me to know everyone's Skill Set

Please see my Screenshot to help But Use Restore Disk Image Not Create Image, I'm very tired today....LOL

[oldfred]

I use rEFInd on a tiny old too small for anything else flash drive for emergency boot. Saved me a couple of times.

But I see a newer version is available.
https://sourceforge.net/projects/refind/
refind_0.14.2-1_amd64.deb

[SUPERFITTER]

I followed your instructions and got the img file on the thumb drive. I booted to the thumb drive at startup and it just kept rebooting the computer. After 4 attempts I unplugged the thumb drive and booted to Ubuntu. I then formatted the thumb drive and reinstalled the img. Retried booting from the thumb drive, same problem kept rebooting computer.

[1fallen]

Weird, but will you now show this:

df -hT

We will try a reinstall of Grub,
Just an example on "my" system, but clipped for easy viewing.

df -hT
### Mine is
/dev/sda1                                        vfat      1.1G  6.2M  1.1G   1% /boot/efi

So I now run:

 sudo grub-install /dev/sda
[sudo] password for me: 
Installing for x86_64-efi platform.
Installation finished. No error reported.

If there are errors please post them back here please.

[1fallen]

BTW, You did first format the Thumb Drive to "fat32" first though Right?

[SUPERFITTER]

me@me1:~$ df -hT
Filesystem     Type      Size  Used Avail Use% Mounted on
tmpfs          tmpfs     1.2G  2.1M  1.2G   1% /run
/dev/sda3      ext4      231G   13G  207G   6% /
tmpfs          tmpfs     5.8G     0  5.8G   0% /dev/shm
tmpfs          tmpfs     5.0M  4.0K  5.0M   1% /run/lock
efivarfs       efivarfs   64K  1.6K   58K   3% /sys/firmware/efi/efivars
/dev/sda1      vfat      511M  8.2M  503M   2% /boot/efi
tmpfs          tmpfs     1.2G  1.7M  1.2G   1% /run/user/1000
/dev/sdb1      ext4      458G   28K  435G   1% /media/me/fc6a8a81-4408-4920-8c49-ca7aaa8810d4
/dev/sdc3      ntfs3     448G   79G  370G  18% /media/me/New Volume
/dev/sdc2      ntfs3     484G   80M  484G   1% /media/me/626EAB593C1543F4
me@me1:~$  sudo grub-install /dev/sda
[sudo] password for me: 
Installing for x86_64-efi platform.
Installation finished. No error reported.
me@me1:~$ Installing for x86_64-efi platform
Installing: command not found
me@me1:~$ Installation finished. No error reported
Installation: command not found
me@me1:~$

Formatted to fat 32

[1fallen]

Formatted to fat 32

Oh goodness I hope that format was to the Thumb Drive, for rEFInd, and nothing Else.

Any way what now will this show, paste back here to see please:

sudo update-grub

Ive been outside in my garden.

[yancek]

Has the editing you have been doing all been while booted into Ubuntu as that should be the primary boot OS according to the boot repair report (/dev/sda3)? In an earlier post you show zorin themes in the /etc/default/grub file. Were you booted into Zorin? Or do you have that entry in the Ubuntu file?

GRUB_THEME=/usr/share/grub/themes/zorin/theme.txt

Your boot repair report shows Zorin on sda2, Ubuntu on sda3 and Mint on sda4. Have you run sudo update-grub while booted into Ubuntu? If you have, you should have watched the output to see if entries are detected and added to the Ubuntu Grub menu. This is because your grub.cfg file on the EFI partition is pointing to the grub.cfg file on sda3, Ubuntu and that is the menu you should see if you have made the proper change in the /etc/default/grub file on Ubuntu.

If you had Grub installed to Zorin and Mint, the entries below when added to the grub.cfg file on Ubuntu should boot Zorin and Mint. Copy the entries there and save the change in the Ubuntu grub.cfg file. Save the changes and reboot. Do NOT run update-grub. If the entries boot, you can then put the changes in the 40_custom file of /etc/grub.d, save the changes and update Grub.

menuentry "Zorin-sda2"{
search.fs_uuid 2df6acb3-3b03-4e8c-b475-e4b78cbf9522 root hd0,gpt2
set prefix=($root)'/boot/grub'
configfile $prefix/grub.cfg
}

menuentry "Mint-sda4"{
search.fs_uuid 7d6bc9c1-ea82-4aa6-9f87-8bf205487a4d root hd0,gpt4
set prefix=($root)'/boot/grub'
configfile $prefix/grub.cfg
}

[1fallen]

I'm out now way too many cooks here>

Good Luck

[SUPERFITTER]

me@me1:~$ sudo update-grub
[sudo] password for me: 
Sourcing file `/etc/default/grub'
Sourcing file `/etc/default/grub.d/init-select.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-6.5.0-28-generic
Found initrd image: /boot/initrd.img-6.5.0-28-generic
Found linux image: /boot/vmlinuz-6.5.0-18-generic
Found initrd image: /boot/initrd.img-6.5.0-18-generic
Memtest86+ needs a 16-bit boot, that is not available on EFI, exiting
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Found Zorin OS 17.1 (17) on /dev/sda2
Found Linux Mint 21.3 Virginia (21.3) on /dev/sda4
done
me@me1:~$