Entire PC backups in Acronis True Image started to fail with error "Unknown status" after Windows Sandbox feature of Windows 10 was enabled.
Windows Sandbox is an optional feature in Windows 10 that appeared in May 2019 Update (Version 1903). It is not enabled automatically. One has to mark the corresponding checkbox in Windows Features list.
Backing up the entire machine is the most complete way to protect your data. We recommend that you choose this option when you are not sure which data you need to protect. When you select Entire PC/Entire Mac as a backup type, Acronis Cyber Protect Home Office(formerly Acronis True Image) backs up all your internal hard drives in disk mode. The backup contains the operating system, installed programs, system settings, and all your personal data including your photos, music, and documents.