ProFTPD cannot support both FTPS and SFTP for the same host

After an upgrade of ProFTPD to the version 1.3.8 one can see the error: 

mod_sftp/1.1.1: Server 'ProFTPd': cannot support both FTPS (TLSEngine on) and SFTP (SFTPEngine on) for the same host

Here is a guide on how to fix it on a server with DirectAdmin.

IMPORTANT: The steps below will disable FTPs on your server, forcing you to use sFTP with your FTP-credentials. Do not follow the steps, if you're not sure to understand all the consequences.

perl -pi -e 's/TLSEngine.*/TLSEngine off/' /etc/proftpd.conf

And restart proftpd:

systemctl restart proftpd

Copy the updated file to a "custombuild" folder to let the changes to survive future updates:

mkdir -p /usr/local/directadmin/custombuild/custom/proftpd/conf/
\cp -p /etc/proftpd.conf /usr/local/directadmin/custombuild/custom/proftpd/conf/

That's it.

Another solution: sFTP with FTPs

It's expected that ProFTPd on a server is already compiled with a support of sFTP and there is a file /etc/proftpd.sftp.conf existing on the server.

If you still need sFTP with FTPs on the same server, then you might install an updated config from the link: 

• https://github.com/poralix/directadmin-utils/blob/master/sftp/proftpd.conf

In order to install the updated config from Poralix's GitHub repository on a Directadmin server run the following commands as root:

mkdir -p /usr/local/directadmin/custombuild/custom/proftpd/conf/
cd /usr/local/directadmin/custombuild/custom/proftpd/conf/
wget https://raw.githubusercontent.com/poralix/directadmin-utils/master/sftp/proftpd.conf -O proftpd.conf

and then re-install proftpd:

cd /usr/local/directadmin/custombuild/
./build proftpd

Have fun!