Repairing the booting system with Boot-repair

Hello everyone,

I am working on Ubuntu BionicBeaver 18.04.3.
The boot of my computer has stopped to work for an unknown reason, I am now limited to the GNU GRUB window.

I have tried to initialize the kernel, as written here:

https://askubuntu.com/questions/8839...b-command-line

But vmlinuz and initrd are not in the boot repository, nor anywhere in the accessible gpt1 and gpt2 folders.

Therefore, I have tried another method, using the tool Boot-repair following the guidelines of this tutorial:

https://www.howtogeek.com/114884/how...ntu-wont-boot/

Unfortunately, the Boot-repair tool installation is not working.

Code:ubuntu@ubuntu:~$ sudo apt-get install -y boot-repair
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
boot-repair : Depends: boot-sav but it is not going to be installed
E: Unable to correct problems, you have held broken packages.Have anyone encounter that problem?