Please read documentation:
https://winscp.net/eng/docs/session_url

I have an a script that is unable to initiate a FTP session when using a session URL. I can do this, however, when manually signing-in (using either a stored session or the command line). I am now wondering if special characters are the cause of my problems. My password is inside my session URL (ftp://username:password@host...). It contains a +, &, ~, and an =. I know the + is special. Are any of the other characters? Thank you!