When upgrading an undercloud from Pike to Queens, it is failing with :
2017-12-18 05:53:59,003 INFO: dib-run-parts lun dic 18 05:53:59 EST 2017 Running /usr/libexec/os-refresh-config/post-configure.d/80-seedstack-masquerade
2017-12-18 05:53:59,005 INFO: + RULES_SCRIPT=/var/opt/undercloud-stack/masquerade
2017-12-18 05:53:59,005 INFO: + . /var/opt/undercloud-stack/masquerade
2017-12-18 05:53:59,005 INFO: ++ IPTCOMMAND=iptables
2017-12-18 05:53:59,006 INFO: ++ [[ 192.0.2.1 =~ : ]]
2017-12-18 05:53:59,006 INFO: ++ iptables -w -t nat -F BOOTSTACK_MASQ_NEW
2017-12-18 05:53:59,008 INFO: iptables: No chain/target/match by that name.
2017-12-18 05:53:59,009 INFO: ++ true
2017-12-18 05:53:59,009 INFO: ++ iptables -w -t nat -D POSTROUTING -j BOOTSTACK_MASQ_NEW
2017-12-18 05:53:59,010 INFO: iptables v1.4.21: Couldn't load target `BOOTSTACK_MASQ_NEW':No such file or directory
2017-12-18 05:53:59,010 INFO:
2017-12-18 05:53:59,010 INFO: Try `iptables -h' or 'iptables --help' for more information.
2017-12-18 05:53:59,010 INFO: ++ true
2017-12-18 05:53:59,010 INFO: ++ iptables -w -t nat -X BOOTSTACK_MASQ_NEW
2017-12-18 05:53:59,011 INFO: iptables: No chain/target/match by that name.
2017-12-18 05:53:59,011 INFO: ++ true
2017-12-18 05:53:59,011 INFO: ++ iptables -w -t nat -N BOOTSTACK_MASQ_NEW
2017-12-18 05:53:59,012 INFO: ++ NETWORK=192.0.2.0/24
2017-12-18 05:53:59,012 INFO: ++ iptables -w -t nat -A BOOTSTACK_MASQ_NEW -s 192.0.2.0/24 '!' -d 192.0.2.0/24 -j MASQUERADE
2017-12-18 05:53:59,013 INFO: ++ iptables -w -t nat -I POSTROUTING -j BOOTSTACK_MASQ_NEW
2017-12-18 05:53:59,014 INFO: ++ iptables -w -t nat -F BOOTSTACK_MASQ
2017-12-18 05:53:59,015 INFO: ++ iptables -w -t nat -D POSTROUTING -j BOOTSTACK_MASQ
2017-12-18 05:53:59,016 INFO: ++ iptables -w -t nat -X BOOTSTACK_MASQ
2017-12-18 05:53:59,017 INFO: ++ iptables -w -t nat -E BOOTSTACK_MASQ_NEW BOOTSTACK_MASQ
2017-12-18 05:53:59,018 INFO: ++ iptables -w -D FORWARD -j REJECT --reject-with icmp-host-prohibited
2017-12-18 05:53:59,019 INFO: iptables: No chain/target/match by that name.
2017-12-18 05:53:59,019 INFO: ++ true
2017-12-18 05:53:59,019 INFO: + iptables-save
2017-12-18 05:53:59,026 INFO: dib-run-parts lun dic 18 05:53:59 EST 2017 80-seedstack-masquerade completed
iptables -L is not showing this rule
I have to say this is not a fatal error and that the process continues. Although you can see the errors in the logs, they are being ignored.