I decided to figure out how to recover data on a disk if the system does not start. It's better to do it before it happens;)
Since there is no definitive correct answer for Linux Mint 18.3 KDE anywhere, I had to find a solution myself.
Good topic for other OS like "Ubuntu": https://askubuntu.com/questions/238047/how-do-i-mount-an-encrypted-home-directory-on-another-ubuntu-machine
sudo ecryptfs-managerand exit (select 4 => Enter) (see bug 455709mount: mount(2) failed: No such file or directory)/home/UserNamedirectory by checking every device in Dolphin. In my case, it is located on a separate volume (But in your case, most likely this path will be inside thehomefolder like:/media/mint/1234567-1233-1233-32423-1a95b2c5dc68/home/UserName)Alt + .for show hidden filesGo to
.ecryptfsfolder inside and try to find.Privatefolder (in every new Folder you have to "Show hidden files" by pressingAlt + .!!!)As final your
.Privatefolder:F4for opening console hereecryptfs-recover-private ./.Private(Passphrase is your login PC Password !!! )/tmp/ecryptfs.JSiaYsbzdirectory usingcdp.s. Use the flag
--rw(in step 9) to mount the encrypted filesystem as read and write (read only as default!)