Error Application Exception Batch Statement Upload Failed. Bad Request an Item with the Sam Key has Already been Added when Uploading Statements to DonorCentral

This is caused by the contents file have duplicated entries for the pdf files. For example, if there are 20 pdfs there should be 20 corresponding lines in the contents file that match the pdfs. When this issue occurs, you may see 60 lines instead of 20 with the lines for each statement being replicated three times.

The solution is to remove the duplicates from the contents file, save the file, re-zip the statements and upload to DonorCentral and the error will not occur.