I have download FileZilla server and I am trying to create a server using the FileZilla software. I have used a new port add a user and from the FileZilla client I tried to enter to the server. Everything worked fine. However when I closed the FileZilla server and tried to reopen again I got the following:
Connecting to server 127.0.0.1:port... Connected, waiting for authentication Protocol error: Unknown protocol identifier (0x50 0x50 0x48). Most likely connected to the wrong port. Connection to server closed.
What is that issue? Now I cant use any option of FileZilla sotware from menu. Every option is marked on gray (unavailable) and I am receiving constantly this message.
EDIT: with the suggested answer from @Martin Prikryl I am receiving from the server interface the following:
Connected, waiting for authentication Logged on Warning: FTP over TLS is not enabled, users cannot securely log in.
and from the client:
Status: Connecting to 127.0.0.1:12321... Status: Connection established, waiting for welcome message... Response: FZS Response: S
Response: D Error: Connection timed out after 20 seconds of inactivity Error: Could not connect to server