Problem with accessing backup device after system upgrade to version 4.3.0

[alimirjamali]

Oh. That issue. It was discussed here (and the solutions were provided):

Error during 4.3 upgrade

Well I’ve freshly installed 4.3 now and when I try to restore the backup, sys-usb is unable to access the external device and give this error: Not authorized to perform operation (polkit authority not available and caller is not uid 0). This is critical for me. What should I do now?