Are you seeing the following error in your FileZilla FTP client? If so, I have the solution for you.

Status:    Connection established, waiting for welcome message...
Status:    Initializing TLS...
Status:    Verifying certificate...
Status:    TLS connection established.
Status:    Logged in
Status:    Starting download of /domains/taskini/.htaccess
Status:    File transfer successful, transferred 260 bytes in 1 second
Status:    Disconnected from server
Response:    421 Timeout - try typing a little faster next time
Error:    GnuTLS error -110 in gnutls_record_recv: The TLS connection was non-properly terminated.
Response:    421 Timeout - try typing a little faster next time
Error:    GnuTLS error -8: A packet with illegal or unsuported version was received
Status:  Connection attempt failed with "ECONNABORTED" - Connection aborted
Error:   Disconnected from server

This is what happened to me. Last week, I opened the FileZilla FTP client to connect to a customer's website and it prompted me to upgrade. I did my work and upgraded after I was done.

The following week, I tried to connect to my server and I couldn't I kept getting an errors:

Error:    GnuTLS error -8: A packet with illegal or unsuported version was received
Status:  Connection attempt failed with "ECONNABORTED" - Connection aborted
Error:   Disconnected from server

The solution:

I downgraded from Version FileZilla_3.56.2_win64-setup.exe to FileZilla_3.55.1_win64-setup.exe

Now it works. Hope that helps.