During installation, you can choose between automatically created users for Acronis services or existing users that you can specify manually. The password for every service accounts is generated automatically.
If changing password for a service user will be required later, do not select automatically created users, but specify existing users. Later, when you need to change this user's password, you can log in as this user and change its password.
If you reset the automatically created password of a service user, you may encounter these issues: