Acronis Cyber Protect Cloud, Acronis Cyber Backup 12.5: Attempt to manually modify Acronis files fails with "Access denied" error

Symptoms

User wants to manually delete a .tib/.tibx backup archive in Explorer, or to modify Acronis configuration files, e.g. to adjust settings of alerts or change default ports for services.

Operation fails with “Access denied” error:

Folder access denied
You need permission to perform this action

Cause

Access to Acronis files may be denied by Acronis Self-Protection.