Tracker csv import errors in v2.0
Just upgraded a site from 1.9.11 to 2.0 and I'm still checking out that everything works the same, and I've got stuck with importing csv files to Trackers. The site has a number of existing Trackers that all seem to work OK but when I tried the csv import of some test data I got the error msg "Duplicate header names".
Thinking I had just screwed up something I exported all the existing data with all the fields and simply tried to reimport this file - but got the same error message. Have tried several more things to see if I could figure out what is happening, including duplicating the existing Tracker - but I keep getting this same error.
Can anyone tell me what the error message actually means and what I could be doing wrong.
Thanks
Geoff