“Authentication failed because the remote party has closed the transport stream” when transferring to/from FTP server over TLS/SSL using FluentFTP

Question

I have used FluentFTP lib im my project to work with FTP via TLS, but some trouble here.

This code working fine:

using (var conn = new F         


        

Answer 1

It seems to be due to a lack of TLS session resumption support in FluenFTP:
https://github.com/robinrodricks/FluentFTP/issues/347

If you confirm that with the server owner, you will have to switch to another FTP library. For a similar question (for an implicit TLS, while you are using an explicit TLS) see:
Upload file to implicit FTPS server in C# with TLS session reuse

Or ask the owner to turn off session resumption requirement (though that's bad from a security point of view).