Hi Juan,
Thank you for the response. Yes, I understood to uncheck. Could you please check the behavior on your end? When files already exist the UI says "Target file exists... " and adds the index.
E.G. "Target file already exists, writing to: C:/- m27_Date_jul08_-001rff01.xisf"
The "01" is added to an already existing file named m27_Date_jul08_-001rff.xisf.
Thanks,
adam