You're getting this error because the username or password on the SFTP tab of the Sync Tool is incorrect.
- Double check the information entered into the tool is matching what was given to you by your implementation consultant or by the CS team.
- It's possible the information you have on file is out of date and the username or password was updated since. Reach out to support if you'd like the information again.
- Search for blank spaces in the Username field. Sometimes people copy and paste with extra space characters in error into either the Password or Username field.