Physical network disconnect - Unusable WinSCP session

How can I reconnect WinSCP session after physical network disconnect?

Call .Close and .Open.

https://winscp.net/eng/docs/library_session_close
https://winscp.net/eng/docs/library_session_open

How can I tell if .open() is needed? Is it prohibitive to call .open() on an already open session?

There's no way to tell that atm. You cannot call .Open if the session is opened. You can try and catch InvalidOperationException.

Hello, How can I continue to upload files to ftp after disconnection? I'm try Close Open session but it's doesn't work! Help plaease!