RRD Rate Upload Error: File processed but threw an exception writing to the database. See trace for more info.

Error is caused by duplicate rows in a column

Example of how to fix when duplicate country codes: 
Please open the file in Excel highlight the first column (A) then find "Conditional Formatting" in the top menu bar > "Highlight cell rules" > "Duplicate Values". This will highlight all duplicates in the country code column. Once this is done you will see any countries that were provided twice. This file is invalid because of the duplicate value(s). You need to reach out to RRD to get the correct value for that row in the file.