Upgrade ASA to 8.4 - The following 'nat' command didn't have a matching 'global' rule on interface and was not migrated - ASA 8.4 (and 8.3) migration

In most cases following warning/error when upgrading to ASA software 8.3 or 8.4 are just informational, and everything went fine. Although you get: NAT migration logs:

The following 'nat' command didn't have a matching 'global' rule on interface 'dmz' and was not migrated.
nat (inside) 1 10.10.10.113 255.255.255.255

And in pre-8.3 configuration you have: NAT migration logs:

global (outside) 1 172.16.1.1 netmask 255.255.255.0
nat (inside) 1 10.10.10.113 255.255.255.255
nat (inside) 1 10.10.10.114 255.255.255.255
nat (inside) 1 10.10.10.115 255.255.255.255
nat (inside) 1 10.10.10.122 255.255.255.255
nat (inside) 1 10.10.10.123 255.255.255.255
nat (inside) 1 10.10.10.124 255.255.255.255

You actually get following entries in 8.3+: NAT migration logs:

object network obj-10.10.10.113-01
 nat (inside,outside) dynamic 172.16.1.1
object network obj-10.10.10.114-01
 nat (inside,outside) dynamic 172.16.1.1
object network obj-10.10.10.115-01
 nat (inside,outside) dynamic 172.16.1.1
object network obj-10.10.10.122-01
 nat (inside,outside) dynamic 172.16.1.1
object network obj-10.10.10.123-01
 nat (inside,outside) dynamic 172.16.1.1
object network obj-10.10.10.124-01
 nat (inside,outside) dynamic 172.16.1.1

So NAT configuration was successfully migrated, and error/warning only means that you didn't have global statement for dmz interface, and only this part of NAT configuration was not migrated. inside-outside part was migrated, and everything is fine.