From e78a50bc1506d84110f77c13a2460512c7b55468 Mon Sep 17 00:00:00 2001
From: Kenneth van Ewijk <kennyboy@live.nl>
Date: Tue, 3 Nov 2015 17:56:52 +0100
Subject: [PATCH] bugfix

---
 ErgometerDoctorApplication/Client/ClientThread.cs | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/ErgometerDoctorApplication/Client/ClientThread.cs b/ErgometerDoctorApplication/Client/ClientThread.cs
index 92aae43..c73d26b 100644
--- a/ErgometerDoctorApplication/Client/ClientThread.cs
+++ b/ErgometerDoctorApplication/Client/ClientThread.cs
@@ -43,11 +43,14 @@ namespace ErgometerDoctorApplication
             switch (command.Type)
             {
                 case NetCommand.CommandType.DATA:
-                    lock (Metingen)
+                    if (command != null && command.Meting != null)
                     {
-                        Metingen.Add(command.Meting);
+                        lock (Metingen)
+                        {
+                            Metingen.Add(command.Meting);
+                        }
+                        window.Invoke(window.updateMetingen, new Object[] { command.Meting });
                     }
-                    window.Invoke(window.updateMetingen, new Object[] { command.Meting });
                     break;
                 case NetCommand.CommandType.CHAT:
                     ChatMessage chat = new ChatMessage(command.DisplayName, command.ChatMessage, command.IsDoctor);