diff --git a/ErgometerServer/ClientThread.cs b/ErgometerServer/ClientThread.cs
index 1460881..e0cde8c 100644
--- a/ErgometerServer/ClientThread.cs
+++ b/ErgometerServer/ClientThread.cs
@@ -75,7 +75,6 @@ namespace ErgometerServer
                             {
                                 name = input.DisplayName;
                                 loggedin = true;
-                                Console.WriteLine(name + " (client) connected with password: " + input.Password);
                                 FileHandler.CreateSession(session, name);
                             }
                         }
@@ -95,7 +94,6 @@ namespace ErgometerServer
                         {
                             chat.Add(new ChatMessage(name, input.ChatMessage, false));
                             server.SendToDoctor(input);
-                            Console.WriteLine(name + ": " + input.ChatMessage);
                         }
                         else
                             NetHelper.SendNetCommand(client, new NetCommand(NetCommand.ResponseType.NOTLOGGEDIN, session));
@@ -108,8 +106,17 @@ namespace ErgometerServer
                         FileHandler.WriteChat(session, chat);
                         client.Close();
                         break;
+                    case NetCommand.CommandType.ERROR:
+                        Console.WriteLine("An error occured, assuming client disconnected");
+                        loggedin = false;
+                        running = false;
+                        Console.WriteLine(name + " logged out due to an error");
+                        FileHandler.WriteMetingen(session, metingen);
+                        FileHandler.WriteChat(session, chat);
+                        client.Close();
+                        break;
                     default:
-                        throw new FormatException("Unknown command");
+                       throw new FormatException("Unknown command");
                 }
             }
 
diff --git a/ErgometerServer/DoctorThread.cs b/ErgometerServer/DoctorThread.cs
index 2dc6a40..f3ed1a4 100644
--- a/ErgometerServer/DoctorThread.cs
+++ b/ErgometerServer/DoctorThread.cs
@@ -100,6 +100,12 @@ namespace ErgometerServer
                                 throw new FormatException("Unknown Command");
                         }
                         
+                        break;
+                    case NetCommand.CommandType.ERROR:
+                        Console.WriteLine("An error occured, assuming docter disconnected");
+                        running = false;
+                        Console.WriteLine("Doctor logged out due to an error");
+                        client.Close();
                         break;
                     default:
                         throw new FormatException("Unknown Command");
diff --git a/ErgometerServer/ErgometerServer.csproj b/ErgometerServer/ErgometerServer.csproj
index 03ff5a0..67b48bc 100644
--- a/ErgometerServer/ErgometerServer.csproj
+++ b/ErgometerServer/ErgometerServer.csproj
@@ -37,6 +37,10 @@
       <SpecificVersion>False</SpecificVersion>
       <HintPath>..\..\..\ErgometerLibrary\ErgometerLibrary\ErgometerLibrary\bin\Debug\ErgometerLibrary.dll</HintPath>
     </Reference>
+    <Reference Include="Newtonsoft.Json, Version=7.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
+      <HintPath>..\packages\Newtonsoft.Json.7.0.1\lib\net45\Newtonsoft.Json.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="System" />
     <Reference Include="System.Core" />
     <Reference Include="System.Xml.Linq" />
@@ -49,11 +53,13 @@
   <ItemGroup>
     <Compile Include="ClientThread.cs" />
     <Compile Include="DoctorThread.cs" />
+    <Compile Include="FileHandler.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Server.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />
+    <None Include="packages.config" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
diff --git a/ErgometerServer/FileHandler.cs b/ErgometerServer/FileHandler.cs
new file mode 100644
index 0000000..e0f6a46
--- /dev/null
+++ b/ErgometerServer/FileHandler.cs
@@ -0,0 +1,165 @@
+using ErgometerLibrary;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+namespace ErgometerServer
+{
+    public class FileHandler
+    {
+        public static string DataFolder { get; } = Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.MyDocuments), "Ergometer");
+        public static string UsersFile { get; } = Path.Combine(DataFolder, "users.ergo");
+
+        public static void CheckStorage()
+        {
+            if (!Directory.Exists(DataFolder))
+            {
+                Directory.CreateDirectory(DataFolder);
+            }
+
+            if (!File.Exists(UsersFile))
+            {
+                using (Stream stream = File.Open(UsersFile, FileMode.Create))
+                {
+                    BinaryWriter writer = new BinaryWriter(stream);
+                    writer.Write(1);
+                    writer.Write("Doctor0tVfW");
+                    writer.Write("password");
+                }
+            }
+        }
+
+        //SESSION 
+        public static int GenerateSession()
+        {
+            string[] existingSessions = Directory.GetDirectories(DataFolder);
+
+            Random rand = new Random();
+            int sessionID = rand.Next(0, int.MaxValue);
+
+
+            while (existingSessions.Contains(sessionID.ToString()))
+            {
+                sessionID = rand.Next(int.MinValue, int.MaxValue);
+            }
+
+            return sessionID;
+        }
+
+        public static void CreateSession(int session, string naam)
+        {
+            Directory.CreateDirectory(GetSessionFolder(session));
+
+            using (File.Create(Path.Combine(GetSessionFile(session)))) ;
+            using (File.Create(Path.Combine(GetSessionMetingen(session)))) ;
+            using (File.Create(Path.Combine(GetSessionChat(session)))) ;
+
+            File.WriteAllText(GetSessionFile(session), naam + Environment.NewLine + Helper.Now);
+            Console.WriteLine("Created session at " + Helper.MillisecondsToTime(Helper.Now));
+        }
+
+        public static void WriteMetingen(int session, List<Meting> metingen)
+        {
+            if (metingen.Count <= 15 && Directory.Exists(GetSessionFolder(session)))
+            {
+                Directory.Delete(GetSessionFolder(session), true);
+            }
+            else
+            {
+                string json = Newtonsoft.Json.JsonConvert.SerializeObject(metingen);
+                File.WriteAllText(GetSessionMetingen(session), json);
+                Console.WriteLine("Writing metingen: " + GetSessionMetingen(session));
+            }
+        }
+
+        public static List<Meting> ReadMetingen(int session)
+        {
+            object metingString = Newtonsoft.Json.JsonConvert.DeserializeObject(GetSessionMetingen(session));
+            Console.WriteLine("Reading metingen: " + GetSessionMetingen(session));
+            return (List<Meting>)metingString;
+        }
+
+        public static int[] GetAllSessions()
+        {
+            string[] directories = Directory.GetDirectories(DataFolder);
+            int[] sessions = new int[directories.Length];
+            for (int i = 0; i < directories.Length; i++)
+            {
+                sessions[i] = int.Parse(directories[i]);
+            }
+            return sessions;
+        }
+
+        public static void WriteChat(int session, List<ChatMessage> chat)
+        {
+            if (chat.Count <= 15 && Directory.Exists(GetSessionFolder(session)))
+            {
+                Directory.Delete(GetSessionFolder(session), true);
+            }
+            else
+            {
+                string write = "";
+                foreach (ChatMessage c in chat)
+                {
+                    write += c.ToString() + "\n";
+                }
+
+                File.WriteAllText(GetSessionChat(session), write);
+                Console.WriteLine("Writing chat: " + GetSessionChat(session));
+            }
+        }
+
+        private static string GetSessionFolder(int session)
+        {
+            return Path.Combine(DataFolder, session.ToString());
+        }
+        private static string GetSessionFile(int session)
+        {
+            return Path.Combine(DataFolder, session.ToString(), "session.prop");
+        }
+        private static string GetSessionMetingen(int session)
+        {
+            return Path.Combine(DataFolder, session.ToString(), "metingen.ergo");
+        }
+        private static string GetSessionChat(int session)
+        {
+            return Path.Combine(DataFolder, session.ToString(), "chat.log");
+        }
+
+        //USER MANAGEMENT
+        public static Dictionary<string, string> LoadUsers()
+        {
+            Dictionary<string, string> users = new Dictionary<string, string>();
+
+            using (Stream stream = File.Open(UsersFile, FileMode.Open))
+            {
+                BinaryReader reader = new BinaryReader(stream);
+                int count = reader.ReadInt32();
+                for (int n = 0; n < count; n++)
+                {
+                    var key = reader.ReadString();
+                    var value = reader.ReadString();
+                    users.Add(key, value);
+                }
+            }
+
+            return users;
+        }
+
+        public static void SaveUsers(Dictionary<string, string> users)
+        {
+            using (Stream stream = File.Open(UsersFile, FileMode.Open))
+            {
+                BinaryWriter writer = new BinaryWriter(stream);
+                writer.Write(users.Count);
+                foreach (var kvp in users)
+                {
+                    writer.Write(kvp.Key);
+                    writer.Write(kvp.Value);
+                }
+                writer.Flush();
+            }
+        }
+    }
+}
diff --git a/ErgometerServer/Server.cs b/ErgometerServer/Server.cs
index 787d1f7..e0dfbf8 100644
--- a/ErgometerServer/Server.cs
+++ b/ErgometerServer/Server.cs
@@ -85,10 +85,6 @@ namespace ErgometerServer
             {
                 doctor.sendToDoctor(command);
             }
-            else
-            {
-                Console.WriteLine("No doctor connected to the server yet");
-            }
         }
 
         public void BroadcastToClients(NetCommand command)
@@ -131,8 +127,6 @@ namespace ErgometerServer
             string pass;
             bool isOk = users.TryGetValue(name, out pass);
 
-            Console.WriteLine($"Checking {name}, {password}: found {isOk} with response {pass}");
-
             if (!isOk) return false;
 
             return pass == password;
diff --git a/ErgometerServer/packages.config b/ErgometerServer/packages.config
new file mode 100644
index 0000000..64b5d8e
--- /dev/null
+++ b/ErgometerServer/packages.config
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="Newtonsoft.Json" version="7.0.1" targetFramework="net452" />
+</packages>
\ No newline at end of file