Mountain Lion: Migration Assistant unexpectedly quits when migrating to a Mac that has Back to My Mac enabled
Symptoms
Migration Assistant may unexpectedly quit when migrating to Mountain Lion if the destination Mac has Back to my Mac enabled.
Resolution
On the destination Mac:
- From the Apple () menu, choose System Preferences.
- From the View menu, choose iCloud.
- Turn off Back to My Mac.
After your migration has successfully completed, you can turn Back To My Mac on again in iCloud preferences.
Read more http://support.apple.com/kb/TS4345