Error in module 3 milestone 3 (connect_from_port_20)

so I completed the milestone 2 by running the FTP transfer file. After that when I made changes in vsftpd.conf for milestone 3 and duplicate variable. Now, I got the following error

500 OOPS: bad bool value in config file for: connect_from_port_20

please guide me to solve this error

Remove that extra space after NO on line 134.

tried but nothing happens…

since I am getting bool error, so, I tried to change the value to yes.
And this works for me.