I’ve been trying to troubleshoot the “import csv line items” tool (from Tiller Community Solutions) for quite a while. I’ve downloaded the correct Amazon order sheets “Retail.OrderHistory.1.csv” and every time I try to upload it into the tool, I receive the following error message: “The importer does not recognize the uploaded file. Check that you are uploading a supported file type.”
I’ve verified the file type, applied different python scripts to convert the .csv columns into the needed headers, completed the Categorization process for transactions and descriptions (i.e., “[Amazon Item”]) read community board posts (and the instructions: Docs: Import CSV Line Items ), and still hit this error. Any advice or troubleshooting guidance would be GREATLY appreciated! Thank you (Heather, Randy, anyone 
).
I had the same experience trying to convert the new format to the old format. Since that function is no longer supported by the creators, it’s going to be continual wack a mole with Amazon. You are welcome to try my solution documented here. I import about once a month, so hopefully I’ll be quick about fixing any breaks. GitHub - daveinlosbarriles/TillerAmazonOrdersCSVImport · GitHub
Thank you, Dave! This is excellent. Look forward to putting it to use (and not going in circles any more) 
Not relevant to the issue, but thought I’d share. I had no idea the csv importer supported amazon order history! I just use it for apple card. I had painstakingly built a custom sheet to identify and reconcile amazon order history with credit card txns.
good luck, let me know if you have any questions.
Thanks for sharing your solution here @daveahlers !
