Cannot activate an external harddrive - com.apple.DiskManagement.disenter errore -119930868

Good morning, this morning, two of my external hard drives are no longer recognized by my Mac. The hard drives appear to boot, but they won't activate. I worked with them without any problems until yesterday morning, but since this morning they no longer work, for no apparent reason. I've already tried on another Mac with the same operating system, but without success.

From the Disk Utility panel, I get these messages:

[Edited by Moderator]