Q: An error occurs stating I don't have permission to access some of the items when I'm about 80% through copying my backups to a new hard drive. Any ideas?

I had exactly the same problem last week: I was logged in as an administrator, and I authenticated with my administrator password, and I tried it at least twice, but, both times, after copying about 20%, Finder displayed the message "The operation can’t be completed because you don’t have permission to access some of the items."

So I tried it a different way -- I used the "Restore" feature of Disk Utility to duplicate the old drive onto the new one, following a procedure similar to the one described here: Disk Utility 12.x: Duplicate a disk, CD, or DVD. So far the new backup drive is working fine. The only disadvantage to this approach seems to be that it always erases whatever is on the new drive first, so if anything is there that you want to keep then you'll need to copy it somewhere else before running Disk Utility.

Many thanks for this advice, I used this method yesterday after wasting hours using Apple's suggested method. after spending many hours "preparing to copy" it started to copy the files and then up came the "The operation can't be completed because you don't have permission to access some of the items" message.

My Time Machine backups go back to 2012, Apple should offer this as a much better and more efficient method of using a new hard drive for these backups.

Thanks!

Also I've found some problems with permissions using finder.

Disk utility works well, and solve any problem.