The TLS connection was non-properly terminated

Hello

I have been looking all over (almost) the place for a fix, but I am unable to find it.
Using Virtualmin with ProFTPD.
While connecting to ProFTPD with the latest version of FIleZilla, I get the error:

GnuTLS error -110: The TLS connection was non-properly terminated

I am still able to connect, upload and download, but would like to fix this error, which seems might be a security hole.

Anyone stumbled upon this problem and was able to fix it?