As a teacher, when I upload my .csv file, I get an error message that "There are errors in your .csv file"

When you try to add students to your class by uploading a .csv file, if you get the following error message:

"There are errors in your .csv file. Please fix them and resubmit the file."

make sure that:

1. Your columns follow the order:  First name, Last name, Username (optional), Email (if students are over 13 years old)
2. Do NOT include a row at the top with the column names. Only student data should be in the .csv file.