From 2ffca3fe6b365c0b55b3ec0ec525cc578deaf742 Mon Sep 17 00:00:00 2001
From: Mark Whitehorn <kd0aij@gmail.com>
Date: Fri, 25 Oct 2019 21:23:45 -0600
Subject: [PATCH] AP_NavEKF2: add prearm failure message for null core pointer

---
 libraries/AP_NavEKF2/AP_NavEKF2.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/AP_NavEKF2/AP_NavEKF2.cpp b/libraries/AP_NavEKF2/AP_NavEKF2.cpp
index 5f693c4975..12a0d75f5a 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2.cpp
+++ b/libraries/AP_NavEKF2/AP_NavEKF2.cpp
@@ -1455,7 +1455,7 @@ uint32_t NavEKF2::getLastVelNorthEastReset(Vector2f &vel) const
 const char *NavEKF2::prearm_failure_reason(void) const
 {
     if (!core) {
-        return nullptr;
+        return "no EKF2 cores";
     }
     for (uint8_t i = 0; i < num_cores; i++) {
         const char * failure = core[i].prearm_failure_reason();