Make sure that you have following error in /usr/local/psa/var/modules/panel-migrator/sessions/<sessionID>/pmm-agent.<datetime>/shallow-dump.log:
ERROR ffefcf51-a507-4e61-8bfb-ad4fcd7aaeaf Error: file '/etc/quota.conf' is not a text file
Can't use string ("") as a subroutine ref while "strict refs" in use at Dumper.pm line 555
In this case, just create missing file on cPanel server:
Resolution:
# touch /etc/quota.conf