These are the possible causes of the issue:
1. Platforms column or Due date column information was not provided - either of them was left blank
2. The rows are less than 3 on the CSV file
3. Syntax error in the header column: e.g. "Date" or "Due Dates" instead of "Due Date". Please do not edit the header column.
4. The file was saved as Excel and not as a CSV file.