Status update: Using 12 inch USB male to USB male cable --tried both with and without this cable. Both computers are on the same local WiFi network. Sharing is turned on on both computers. Firewall is off on both computers. Source (old) computer is an original 11 inch MacBook Air (late 2010) running Sierra 10.12.6. Target (newish) computer is a refurbished MacBook Air (early 2015) running Big Sur (11.4). Process freezes with old computer showing that the computer is searching for applications and documents to transfer. New computer shows the old computer icon, says checking old computer, suddenly a popup says it cannot connect. I have tried turning off both computers a starting "fresh" several (at least 6) times --always stalls at the same point (cannot connect). Is there a fix for this or am I stuck with a tedious reinstall of all applications and copy of documents to an USB drive and transfer to newer computer?