I got around the issue by not copying all the files aty once. I copied say 50 percent the first copy and then the second 50 percent the second copy.
I think Mac has a bug.
I don't think so as the second time it worked and the drive has been used before as a backup drive.
This is a fairly new drive (less than six months). What I am also concerned about that since the message was so vague, that it could have been on the sending drive. What would be so hard from Apple to give minimal information like which drive caused the problem? I am used to a different environment where the OS was at least help in problem determination.
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