Software index is broken + The application Software Updater has closed unexpectedly

I faced the following error message today:

Software index is broken

It is impossible to install or remove any software. Please use the package manager "Synaptic" or run "sudo apt-get install -f" in a terminal to fix this issue at first.

So I openned a terminal and typed:

sudo apt-get install -f

But then it crashed, I had both the output of the terminal that stuck here:

USER_HERE:~$ sudo apt-get install -f
E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem. 
USER_HERE:~$ sudo dpkg --configure -a
Setting up linux-headers-4.18.0-17-generic (4.18.0-17.18~18.04.1) ...
Processing triggers for initramfs-tools (0.130ubuntu3.7) ...
update-initramfs: Generating /boot/initrd.img-4.18.0-16-generic
Setting up linux-headers-4.15.0-47-generic (4.15.0-47.50) ...

And opened a "crash report" window:

For further details:

How to fix it ?