Copying 84 gigabyte file via USB results in duplicate file warning and case sensitive fail where no duplicate exists
OP's solution:


  in the end opened up my FTP client and transferred the file via my local ethernet. It worked!






  I would highly recommend that you perform a total system backup using Carbon Copy Cloner.
  
  Carbon Copy Cloner does support restoring to a case-insensitive system from a case-sensitive one - see this.


https://superuser.com/a/380358/1038202

  SuperDuper is the best way to clone drives in OS X. You can rename the destination drive in Finder


https://superuser.com/a/20779/1038202
There's also a script on Github, which claims to 


  
  Resolve all case-sensitivity naming conflicts
  Make a fresh TimeMachine backup 
  Flip the backups's case-sensitivity flag 
  Restore from the manipulated backup
  


https://github.com/cr/MacCaseSensitiveConversion