You have received this error message because, the barcodes in the file has not been converted to numbers before saving the file. Its important when working with CSV-files, to edit the format of the barcodes before saving the file. Otherwise the files barcodes will be corrupted.
I order to fix this problem, you have to paste the barcodes into the file ones again. And upload the file.
Below, is a quick guide on how to format barcodes correctly in an already saved CSV file that you open.
Format to numbers
Remove ",00"