You attempt to clone a disk with APFS (Apple File System). Cloning fails with the following error:
An error occured while cloning the disk. Cannot get the APFS contents
APFS is supported only in macOS High Sierra 10.13 and newer. This error occurs if you are trying to clone a disk with APFS file system on macOS Sierra 10.12 or OS X El Capitan 10.11
Earlier versions of macOS do not natively support APFS as it was introduced in macOS High Sierra 10.13
Acronis True Image 2019 for Mac cannot clone a disk with a file system that is not natively supported by the operating system. Disks with APFS can only be cloned on macOS High Sierra 10.13 and newer versions of of macOS.