In my case (on MX Linux - Debian 10 based), I don't have an sftp server installed and I do not want to install it.  I do not need "folder sharing/printing support" for my purposes.  My remote session still opens and works correctly, but I have a X2Go Client popup window that warns about the missing sftp-server binary.  This modal popup freezes the X2Go Client form / UI but the remote session window still works.  If I close the modal popup window, the whole app closes including my remote session window.

sftp-server should be an optional dependency.  There should be a way to close the warning without killing the whole app.  There should be a setting so the warning does not popup every time.