Can I use Migration Assistant after initial setup?

Yes, open Migration Assistant from Applications > Utilities at any time. You do not need to be at the setup screen.

What if usernames conflict?

Migration Assistant will offer to rename the transferred account. You can also create a temporary admin account, migrate, then merge data manually.

Mac Migration Assistant Errors — Transfer Failed & Stuck Progress

Errorsystem

Overview

Fix macOS Migration Assistant errors including stuck transfers, 'could not be copied' errors, network transfer failures, and Time Machine migration issues.

Key Details

Migration Assistant transfers data between Macs via direct cable, Wi-Fi, or Time Machine backup
Transfer can take hours for large data sets — appearing stuck at a percentage for extended periods is normal
Wi-Fi transfers are much slower than Thunderbolt cable transfers
Some applications with copy protection may not transfer successfully
User account conflicts can prevent migration if the same username exists on both Macs

Common Causes

Network instability during Wi-Fi transfer causing disconnections
Insufficient disk space on the destination Mac
Corrupted files on the source Mac causing copy failures
User account name conflict between source and destination
Antivirus or firewall on either Mac blocking the transfer protocol

Steps

1Use Thunderbolt cable instead of Wi-Fi for reliable, fast transfer
2Ensure destination Mac has more free space than source Mac's used space
3On source Mac: run Disk Utility First Aid to fix any file system errors before migration
4Disable firewall on both Macs during transfer: System Settings > Network > Firewall > Off
5If transfer fails repeatedly, use Time Machine backup migration: create backup on external drive, then migrate from it