How to fix 530 Login authentication failed in Pure-FTP on cPanel

As the error states, the issue is that the user can not authenticate properly.  There are 2 common reasons to get this error when making a connection via FTP to a Pure-FTP server on cPanel.

1. Using the wrong username and password
2. Corrupted password database

First, the most common reason, is user error.

• They enter the wrong username.  Either they are putting in @theirdomain.com with they don’t need it, or they are not putting in @theirdomain.com when they do.  If they are trying to login using their cpanel username, they need to make sure they are not including @theirdomain.com in the username.  If they are trying to connect using an additional FTP username they created in their cPanel, then they need to make sure they ARE using @theirdomain.com in their username
• They are entering their password wrong.  Either they have the wrong password, or they are trying to copy and paste the password incorrectly.  When copy and pasting a password, customers have often unknowingly grabbed a whitespace before or after the password.  The best way to determine if this is the case is have them paste the password somewhere they can see it like in notepad, and check to see if it’s pasting a space.

The 2nd most common reason is a corrupt password database.  This is not quite as common as the last reasons, but we have seen this happen a number of times over the years.  Typically, this happens after a cPanel update, or an FTP server update.  Bellow are some of the ways we have found to correct this.

• Switch FTP servers in the WHM, then switch back.  Simply switching to Proftpd to Pure-ftpd will force the passwords to re-synchronize, which rebuids the FTP password database
• Synchronize the passwords from the WHM. in the WHM, click on “Synchronize FTP Passwords”.  This will also re-sync the passwords, which will also rebuild the FTP password database.
• Simply reset the password.  If you reset the password to match what the password should have been, that should correct the issue.  However, they will only help out the one customer you are working with.  So if this is affecting multiple users, then one of the other 2 options above would be a more ideal solution.