Symptoms

Acronis True Image 2021 repeatedly asks for a restart after installation on macOS 11 Big Sur:

To run Acronis True Image, you must restart your Mac.

Cause

macOS prevents one of Acronis True Image kernel extensions from loading.

One restart is required for loading drivers. If Acronis True Image is requesting restart over and over, please follow the solution below.

Solution

This issue has been fixed in Acronis Cyber Protect Home Office (formerly Acronis True Image). If you have an active subscription to Acronis True Image, you can upgrade at no cost.

Solution for earlier versions of the product:

Delete records about kernel extensions from KextPolicy table in macOS Recovery:

1. Boot into macOS Recovery: restart Mac and hold Command (⌘)+R 

   Booting into macOS Recovery environment is obligatory for running the commands below. Access to kernel extensions database is prohibited under live macOS.
2. Open Terminal from the Utilities menu.
3. Change the current directory to the root of the system volume. Usually, its name is "Macintosh HD" or "Mac HD".

   cd "/Volumes/Macintosh HD"

4. Launch sqlite3:

   ./usr/bin/sqlite3

   Note the period . at the beginning of this command and commands in the next steps
5. Open the KextPolicy database:

   .open var/db/SystemPolicyConfiguration/KextPolicy

6. Enter the following queries and confirm their execution with the Enter key:

   DELETE FROM kext_load_history_v3 where team_id = 'ZU2TV78AA6';
   DELETE FROM kext_policy where team_id = 'ZU2TV78AA6';

7. Quit sqlite3 with the following command and reboot the Mac:
   .quit

If the steps above didn't help, there are probably some old Blackberry drivers on the Mac, which prevent True Image from loading. Delete them according to the following guidelines: https://bombich.com/kb/ccc5/some-third-party-storage-drivers-may-cause-hardware-misbehavior

Check the guidelines even if you don't remember having installed any Blackberry drivers, they may have been installed by default.