When attempting to migrate a reseller's subscription without migrating the reseller itself, the attempt fails with the following errors:
PHP Notice: Trying to get property of non-object; File: /usr/local/psa/admin/plib/backup/Conflicts/PleskDataManager.php, Line: 173
PHP Notice: Undefined index: xxx.xxx.xxx.xxx; File: /usr/local/psa/admin/plib/backup/Conflicts/PleskDataManager.php, Line: 180
PHP Fatal error: Call to a member function capability() on a non-object in /usr/local/psa/admin/plib/backup/Conflicts/Resolver/UnfitSettingsResolver.php on line 292
<xxx.xxx.xxx.xxx> is the IP address).
Additionally, the following error can be found in
/var/log/plesk/panel.log when debug mode is enabled:
DEBUG [dbquery]  SQL: SELECT `IP_Addresses`.* FROM `IP_Addresses` AS `IP_Addresses` WHERE (`serviceNodeId` = '')
Debug: Unable to get service node IP for phosting on subscription.tld
<subscription.tld> is the affected subscription name).
This problem was caused by software issue #PPPM-1754
Install Parallels Plesk 12.0.18 MU#9 . The issue was fixed in this microupdate.