Comment 5 for bug 1743091

Sorry I have not tested the new kernel because I fixed the issue on 5th feb 2018 this way: "How I have get out the issue : by restoring the previous Linux Kernel (from the GRUB menu)."
Then the Ubuntu auto-update system did some upgrades, and all is working fine since then:
uname -a
Linux HP-Compaq-6730s 4.13.0-21-generic #24-Ubuntu SMP Mon Dec 18 17:29:35 UTC 2017 i686 i686 i686 GNU/Linux

Today I use a more recent kernel and booting is OK too:
Linux HP-Compaq-6730s 4.10.0-42-generic #46-Ubuntu SMP Mon Dec 4 14:36:05 UTC 2017 i686 i686 i686 GNU/Linux

Perhaps the issue was related to some error on the storage (it's a old 32 GB SSD, that is OK according to the SMART values).

I am sorry to have not tested the v4.15 kernel[0], this is because I have access to this computer only every 3 or 6 months. If this is still useful I may do the test in the next 6 months.