Error - "550 Permission denied on FTP operation" - Linux

If you are unable to do some FTP operations namely delete and create either through ftp client or through code like in php using ftp_delete or ftp_mkdir functions, follow below steps to resolve it.

Edit /etc/vsftpd.conf file as below

sudo gedit /etc/vsftpd.conf

(or) 

sudo nano /etc/vsftpd.conf

Uncomment the following configuration in the file

write_enable=YES

Save the file and restart the FTP service as below

sudo service vsftpd restart

(or)

systemctl restart vsftpd