Final update for anyone else running into this problem.
Opened a support case with VMware. Customer Service was frustrating (to say the least), but the Engineers were great. Sadly, nothing which they recommended resolved the problem. VMware was unable to copy or move or migrate the problem vmdk. There were a variety of reasons and excuses.
Final solution was to download Veeam Backup and Replication (the free version). I couldn't do the QuickMigration, but I was able to manually, offline copy the various components of the VM which I was attempting to move. It took 8 hours to copy the file (due to the size). I was extremely impressed that I could copy two of those files simultaneously in the same 8 hours.
After upgrading the main server, I tried using vMotion to move the VM back to the main server. Two of the three VM's moved with no problem using vMotion. The problem VM crashed ESXi on several attempts. I went back to Veeam and initiated QuickMigration as a live migration. For the most part it was extremely impressive. There was no notable impact on the users during the first 16 hours of the migration. The problem came when it was time to cutover the servers (which occurs automatically... and without warning... under QuickMigration). That portion which normally takes 10 seconds (according to their documentation) had the servers unavailable for 2.5 hours. Sadly it was during a critical portion of their schedule.
That issue set aside, it did resolved the issues automatically and (2.5 hours later) completed the migration without any user intervention.