Migration or backup creation failed with the following error:
Error: domain "domain.package"
Unable to dump IP addresses for mail service
Value cannot be null.
Parameter name: value
An internal issue with id #PPPM-2372 . The issue has been fixed in Plesk 12, MU #38 .
Please install all Plesk microupdates .
If this did not help, contact Odin Technical Support to fix the issue.