Just noticed this in the systray icon's pull-down menu: "Wiederhestellen" should be "Wiederhe_r_stellen".
Also, in Sitzungsvoreinstellungen/Neue Sitzung/Sitzung/Server: "SSH Port" should be "SSH-Port" "RSA/DSA Schlüssel verwenden" should be "RSA-/DSA-Schlüssel verwenden"
In Sitzungsvoreinstellungen/Neue Sitzung/Einstellungen: "Benutze Port Weiterleitung"[...] should be "Benutze Port-Weiterleitung". "DPI Auflösung festlegen" should be "DPI-Auflösung festlegen" or "Auflösung festlegen (in DPI)"
And in Sitzungsvoreinstellungen/Neue Sitzung/freigegebene Ordner: "Benutze SSH Port Weiterleitung"[...] should be "Benutze SSH-Port-Weiterleitung".
"Desktopverknüpfung erzeugen" shows a message containing the string "ohne das x2goclient". I believe this contains two errors, for one, "das" should be "dass", and the commonly accepted name for the client isn't written in all lowercase, IIRC. You will probably want to call it "X2Goclient", "X2GoClient" or "X2Go-Client". This seems to be an inconsistency in the entire client, though (the title bar says "X2Go client", the first item in the "Help" menu says "X2GO Client", clicking on it shows a message containing "the string X2Go Client").
The same message notes that you can use a GPG key or a GPG smartcard to authenticate when using "hidden mode". It does not mention the SSH public key/ssh-agent methods, even though they work just as well. Or maybe you meant that while calling it a GPG key in the message (I've never used GPG-based authentication, so I'm not sure if it requires a smartcard or not)? Anyways - it should be written as "GPG-Smartcard" and "GPG-Schlüssel" or "SSH-Schlüssel" (depending on which one you meant).
Another typo in the same message: "Wollen SIe" should be "Wollen Sie". The same SIe-Sie issue is in the Help/About X2GO Client dialog.
Affected client: http://code.x2go.org/releases/binary-win32/x2goclient/x2goclient-3.99.1.0-se... (now renamed to http://code.x2go.org/releases/binary-win32/x2goclient/x2goclient-3.99.1.0pre... by Mike)
Kind Regards, Stefan