On the Mac two drives, SSD and HDD, on the first system, everything works, the second important data, it "broke". When you turn off and turn on the computer, the drive appears, the files it "includes" and copy the whole thing fails, I get an error and the drive disappears (message about improper eject the disc).
Physically, the drive is split into two - one AFPS, the second HFS (used for Time Mashine system disk). It is likely that the problem is in the past, it's not valuable, but to remove his fear.
If it is to climb (APFS), then the access is very slow. Folder opens long.
Standard Disk utility finds errors but does not fix them, I tried "Disk Drill" also with no result - files does not find, after some operating time the disk crashes. Tried using the console to copy the folders from the package - same result.
460 GB of data - Photos, videos (located in your Photo). The backup data is there, but very old, need it last.
I know that in theory you can remove the drives and format that would get rid of the errors, and then try to recover the data but not sure this will work with APFS disk, do not want to risk.
What else to try? The pictures are very sorry, I have just at this time the daughter was born, there are all her photos up to 2 years. the computer almost didn't fit all the time, so this mess happened. Relying on the reliability of poppies(