I appreciate the responses.
I don’t honestly think there is an issue with my books. Most of them were on this reader before as well as my “back-up” Koba Aura H2O.
I think it’s a Calibre problem. I am trying again to transfer 10 books and it is maxing my memory (4,500MB) and also high CPU.
Last night the job died after 3 plus hours and the application threw a .net error. I tried to cut and paste the details but whole laptop was unresponsive.
I have run a chkdsk on the Reader and it was ok.
I have also run Library Maintenance (Vacuuming?) in Calibre.
I should also mention that I have a large library -60+ GBs/10K+ items - as I have a lot of cookbooks. But the books I am transferring are just regular small novels.