From cbcd0ffb067551382db6120ae025e4ec2932eec6 Mon Sep 17 00:00:00 2001
From: Gus Grubba <gus@grubba.com>
Date: Fri, 26 Oct 2018 13:01:55 -0400
Subject: [PATCH] Don't access value if property doesn't exist.

---
 src/ui/preferences/GeneralSettings.qml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ui/preferences/GeneralSettings.qml b/src/ui/preferences/GeneralSettings.qml
index 8d79dab59..37ea562da 100644
--- a/src/ui/preferences/GeneralSettings.qml
+++ b/src/ui/preferences/GeneralSettings.qml
@@ -504,7 +504,7 @@ QGCView {
                             Item { width: rtkGrid.firstColWidth; height: 1 }
                             QGCButton {
                                 text:               qsTr("Save Current Base Position")
-                                enabled:            QGroundControl.gpsRtk.valid.value
+                                enabled:            QGroundControl.gpsRtk && QGroundControl.gpsRtk.valid.value
                                 Layout.columnSpan:  2
 
                                 onClicked: {
-- 
2.22.0