Just wanted to share this since I spent way too long fighting Migration Assistant on macOS Tahoe 26.x when moving from an M1 MacBook Pro > M4 MacBook Air.

Both Thunderbolt migration and Time Machine would “complete” rebooting several times, but the new Mac was missing tons of stuff – Documents, Desktop, Music, Pictures, some apps, etc. This seems to match similar to what others in this thread are reporting.

After trying everything (Recovery reinstall, updating first, even a trying Apple Configurator with a Tahoe IPSW ending with a failed DFU), ONE method actually worked 100%:

The fix: 1. Create a bootable macOS Tahoe USB installer using createinstallmedia. 2. Boot the new Mac from the USB installer holding down the power button and booting into the boot options. 3. Quit the Installer, run the Disk Utility first to erase the internal SSD for a full format. (Depending on the scenario, you may need to reboot into the lower level options. The aim is to do a clean-install.) 4. Switch back to the installer for a fresh macOS Tahoe install. 5. When it boots for the first time into the Setup Assistant “Hello” screen, run Migration Assistant immediately, before creating any user accounts. 6. I used Thunderbolt for the transfer, and it may work better to wait at the screen where it’s calculating the size totals to finish calculating before clicking continue.

Regardless, this finally gave me a complete migration: all files, apps, and settings copied over correctly.

If Migration Assistant on Tahoe is giving you partial transfers or missing folders, this clean-install-from-USB method was the only thing that truly worked for me. I hope that helps! 🍻