Improve the diagnostics
Saying “Input string was not in a correct format. Click here for help.” without at least indicating the row is very poor. Since there is no verbose mode it is impossible to troubleshoot. I know that the file format is correct because when I truncate the file to 1,3 and 5 rows of data it works fine. My file is attached.
I solved the problem by saving it as a csv file. That showed that there was a blank line at the end of the file. Deleting that line and loading it into Excel again fixed the problem. Better diagnostics would definitely help.