Frank,
I am trying to rename a large number of files on an external back HDD and I get the following error message:
File already exists and overwrite not specified: '/Volumes/HDD for iPad/Drive A Seagate 2 Tb External Inacheck/NEF files/DSC3185.NEF'.
Sure I am doing something wrong!
Are you sure you're doing a Rename Photos and not a Save Photos operation?
Posting a screenshot of your settings in the dialog you're working with usually saves a lot of back-and-forth asking questions. Use the 'Attachments and other options' link when you're composing your reply to this message and there you'll be able to upload your JPEG format screenshot.
I have also noticed there is a check in Sup cat which for some reason I cannot clear.
Where are you seeing this? Screenshots welcome.
-Kirk