Using Migration assistant, I set up the transfer and let the computer transfer the data overnight as recommended by Apple tech. In the morning, about 10 hours later, there is still 266 hours remaining. Wifi connection is strong, about 400gb of data to transfer. Any suggestions?
It seems as though the migration stalled for reasons unknown. Try temporarily changing the Energy Saver settings on both Macs (assuming the source is also a Mac) to "never sleep". Dismiss the ensuing nag; just remember to eventually reset it.
Of course that action shouldn't be required, but if MA gets mired in an unusually time-consuming task it might take so long that the subject Mac goes to sleep... leaving MA waiting forever for it to wake up again... which doesn't happen on its own.
Is this a new Mac? Consider contacting Apple Support, and put them to work for you. The cost of that service is included with a new Mac purchased from Apple.
Slow migration assistant
