Same error:
https://forums.fedoraforum.org/showt...-login-allowed has been solved
You should use ProFTPd wich is what i use for OGP , now switched from a few days to Ptereodactyl, has pre build SSH integrated per user, a little hard to setup but in the end result was awesome and worth it.
For connection
sudo ufw allow 22/tcp (ssh)
sudo ufw allow 21/tcp (ftp)
Dont forget to add passive ports if you are behind a router
sudo ufw allow 55521:55555/tcp
The passive ports must be enabled in proftpd.conf to work , ithink the default passive ports are: 49152:65534 as mine are.
In ptereodactyl every game server has its own user and password cand cannot be controlled from users outside Ptereo Panel only if they been giving root access and gameserver is stopped, just amazing, and secure the servers are running under isolated container means everything you can do to the server does not affect main os/machine (like they are virtualised)