"A comma-separated values (CSV) file is a delimited text file that uses a comma to separate values. Each line of the file is a data record. Each record consists of one or more fields, separated by commas. The use of the comma as a field separator is the source of the name for this file format. A CSV file typically stores tabular data (numbers and text) in plain text, in which case each line will have the same number of fields." (Source: Wikipedia).
Unfortunately, CSV files are not as standardized as they should be. In Europe for example, decimal places are marked by commas rather than dots, which means that semi-colons replace commas to separate values.
Exirio works with the most common, international CSV format. And this means that if you use Excel (and its settings are European) to open Exirio's CSV template, Excel will not "understand" it. And the CSV you try to upload will not work on Exirio.
We are working on a solution, i.e. a smarter CSV function on Exirio to bypass the problem, but in the meantime instead of opening the CSV template you download from Exirio, open a blank Excel sheet. Then click on Data, Import from Text/CSV and the select the downloaded file. Excel will then be able to interpret it and you will see separate columns. You can then populate the file and save it a CSV which should then work with Exirio.