Uploading CSV file keeps failing to import users

I downloaded the CSV header file for importing into user pools and only added to the 2nd line after the header, but it keeps failing no matter what: "Too many users have failed or been skipped during the import." I tried adding placeholder values for the attributes I don't use and tried removing the header line, but it still fails.

When I click "start," it says "pending" for a infinite amount of type and then it says "fail" when I click the refresh button. I'm not sure what could be the issue, can someone guide me to how to fix my issue? I'm only trying to add 1 user, but it still fails.