diff --git a/app/src/main/java/de/sebse/fuplanner/MainActivity.java b/app/src/main/java/de/sebse/fuplanner/MainActivity.java
index be22567..9ab81fd 100644
--- a/app/src/main/java/de/sebse/fuplanner/MainActivity.java
+++ b/app/src/main/java/de/sebse/fuplanner/MainActivity.java
@@ -91,12 +91,12 @@ public class MainActivity extends AppCompatActivity
         LoginToken loginToken = getKVV().easyLogin();
         if (newFragmentPage != FRAGMENT_LOGIN && newFragmentPage != FRAGMENT_STARTUP && newFragmentPage != FRAGMENT_NONE) {
             if (loginToken != null)
-                toLoginState(loginToken, newFragmentPage, newFragmentData);
+                toLoginState(loginToken, newFragmentPage, newFragmentData, true);
             else
                 checkAndDoLogin();
         } else {
             if (loginToken != null)
-                toLoginState(loginToken, getDefaultFragmentAfterLogin(), "");
+                toLoginState(loginToken, getDefaultFragmentAfterLogin(), "", true);
             else
                 checkAndDoLogin();
         }
@@ -227,22 +227,29 @@ public class MainActivity extends AppCompatActivity
 
     private void toLogoutState() {
         changeFragment(FRAGMENT_LOGIN);
+        View offline_header = findViewById(R.id.offline_msg);
+        offline_header.setVisibility(View.GONE);
     }
 
-    private void toLoginState(LoginToken loginToken, int newFragment, String newData) {
+    private void toLoginState(LoginToken loginToken, int newFragment, String newData, boolean onlineMode) {
         if (loginToken == null) {
             toLogoutState();
         } else {
-            toLoginState(loginToken.getFullname(), loginToken.getEmail(), newFragment, newData);
+            toLoginState(loginToken.getFullname(), loginToken.getEmail(), newFragment, newData, onlineMode);
         }
     }
 
-    private void toLoginState(String fullname, String email, int newFragment, String newData) {
+    private void toLoginState(String fullname, String email, int newFragment, String newData, boolean onlineMode) {
         changeFragment(newFragment, newData);
 
         View header = mNavigationView.getHeaderView(0);
         ((TextView) header.findViewById(R.id.login_name)).setText(fullname);
         ((TextView) header.findViewById(R.id.login_mail)).setText(email);
+        View offline_header = findViewById(R.id.offline_msg);
+        if (onlineMode)
+            offline_header.setVisibility(View.GONE);
+        else
+            offline_header.setVisibility(View.VISIBLE);
     }
 
     private void checkAndDoLogin() {
@@ -253,7 +260,7 @@ public class MainActivity extends AppCompatActivity
                 return;
             }
             this.getKVV().login(credentials.getUsername(), credentials.getPassword(), success -> {
-                toLoginState(success, getDefaultFragmentAfterLogin(), "");
+                toLoginState(success, getDefaultFragmentAfterLogin(), "", true);
             }, error -> {
                 log.e(error);
                 toLogoutState();
@@ -365,8 +372,8 @@ public class MainActivity extends AppCompatActivity
 
 
 
-    public void onLoginFragmentInteraction(LoginToken loginToken) {
-        toLoginState(loginToken.getFullname(), loginToken.getEmail(), getDefaultFragmentAfterLogin(), "");
+    public void onLoginFragmentInteraction(LoginToken loginToken, boolean onlineMode) {
+        toLoginState(loginToken.getFullname(), loginToken.getEmail(), getDefaultFragmentAfterLogin(), "", onlineMode);
     }
 
     public void onModulesFragmentInteraction(final String itemID) {
@@ -380,4 +387,18 @@ public class MainActivity extends AppCompatActivity
     public void onTitleTextChange(@StringRes int titleId) {
         setTitle(titleId);
     }
+
+    public void loginTokenInvalid() {
+        //getKVV().invalidate();
+        //checkAndDoLogin();
+        log.d("Login token invalid!");
+    }
+
+    public void refreshFailed(boolean isFailed) {
+        View viewNoConnection = findViewById(R.id.no_connection_msg);
+        if (isFailed)
+            viewNoConnection.setVisibility(View.VISIBLE);
+        else
+            viewNoConnection.setVisibility(View.GONE);
+    }
 }
diff --git a/app/src/main/java/de/sebse/fuplanner/fragments/LoginFragment.java b/app/src/main/java/de/sebse/fuplanner/fragments/LoginFragment.java
index 0748ab7..267c162 100644
--- a/app/src/main/java/de/sebse/fuplanner/fragments/LoginFragment.java
+++ b/app/src/main/java/de/sebse/fuplanner/fragments/LoginFragment.java
@@ -69,7 +69,7 @@ public class LoginFragment extends Fragment {
                     Button offline_btn = v.findViewById(R.id.btn_offline);
                     offline_btn.setVisibility(View.VISIBLE);
                     offline_btn.setText(v.getResources().getString(R.string.enter_offline_mode, modules.getToken().getUsername()));
-                    offline_btn.setOnClickListener(v1 -> mListener.onLoginFragmentInteraction(modules.getToken()));
+                    offline_btn.setOnClickListener(v1 -> mListener.onLoginFragmentInteraction(modules.getToken(), false));
                 }
             }
         } catch (IOException e) {
@@ -102,7 +102,7 @@ public class LoginFragment extends Fragment {
                         progressDialog.dismiss();
                         gauth.setLoginState(username, password);
                         if (mListener != null)
-                            mListener.onLoginFragmentInteraction(success);
+                            mListener.onLoginFragmentInteraction(success, true);
                     }, error -> {
                         progressDialog.dismiss();
                         log.e("Error on KVV login!", error);
@@ -148,6 +148,6 @@ public class LoginFragment extends Fragment {
      * >Communicating with Other Fragments</a> for more information.
      */
     public interface OnLoginFragmentInteractionListener {
-        void onLoginFragmentInteraction(LoginToken loginToken);
+        void onLoginFragmentInteraction(LoginToken loginToken, boolean onlineMode);
     }
 }
diff --git a/app/src/main/java/de/sebse/fuplanner/services/KVV/KVV.java b/app/src/main/java/de/sebse/fuplanner/services/KVV/KVV.java
index d796585..1bb80a1 100644
--- a/app/src/main/java/de/sebse/fuplanner/services/KVV/KVV.java
+++ b/app/src/main/java/de/sebse/fuplanner/services/KVV/KVV.java
@@ -10,6 +10,7 @@ import java.util.HashMap;
 
 import de.sebse.fuplanner.services.KVV.types.LoginToken;
 import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.tools.MainAcitivityListener;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
 
@@ -23,8 +24,11 @@ public class KVV {
     private boolean isLoginPending = true;
     private ArrayList<LastTokenCallback> updatingList;
     private HashMap<String, Object> addons = new HashMap<>();
+    private MainAcitivityListener mListener;
 
     public KVV(Context context) {
+        if (context instanceof MainAcitivityListener)
+            mListener = (MainAcitivityListener) context;
         this.context = context;
         this.updatingList = new ArrayList<>();
     }
@@ -54,14 +58,18 @@ public class KVV {
     }
 
     public void logout() {
-        if (lastToken != null) {
-            lastToken.delete(this.context);
-            lastToken = null;
-        }
         KVVModuleList modules = (KVVModuleList) addons.get("modules");
         if (modules != null) {
             modules.deleteModulesOffline(this.context);
         }
+        invalidate();
+    }
+
+    public void invalidate() {
+        if (lastToken != null) {
+            lastToken.delete(this.context);
+            lastToken = null;
+        }
         addons.clear();
         this.isLoginPending = true;
     }
@@ -77,7 +85,7 @@ public class KVV {
                 modules = new KVVModuleList(KVV.this.context, token);
                 addons.put("modules", modules);
             }
-            modules.getModule(id, saveOnCallback(modules, callback), error, forceRefresh);
+            modules.getModule(id, saveOnCallback(modules, callback, forceRefresh), errorOnCallback(error), forceRefresh);
         });
     }
 
@@ -92,7 +100,7 @@ public class KVV {
                 modules = new KVVModuleList(KVV.this.context, token);
                 addons.put("modules", modules);
             }
-            modules.getModuleList(saveOnCallback(modules, callback), error, forceRefresh);
+            modules.getModuleList(saveOnCallback(modules, callback, forceRefresh), errorOnCallback(error), forceRefresh);
         });
     }
 
@@ -101,7 +109,7 @@ public class KVV {
     }
 
     public void getModuleDetails(Modules.Module module, final NetworkCallback<Pair<Modules.Module, Boolean>> callback, final NetworkErrorCallback error, boolean forceRefresh) {
-        getModulePart(modules -> modules.getModuleDetails(module, saveOnCallback(modules, callback), error, forceRefresh));
+        getModulePart(modules -> modules.getModuleDetails(module, saveOnCallback(modules, callback, forceRefresh), errorOnCallback(error), forceRefresh));
     }
 
     public void getModuleAnnouncements(Modules.Module module, final NetworkCallback<Modules.Module> callback, final NetworkErrorCallback error) {
@@ -109,7 +117,7 @@ public class KVV {
     }
 
     public void getModuleAnnouncements(Modules.Module module, final NetworkCallback<Modules.Module> callback, final NetworkErrorCallback error, boolean forceRefresh) {
-        getModulePart(modules -> modules.getAnnouncements(module, saveOnCallback(modules, callback), error, forceRefresh));
+        getModulePart(modules -> modules.getAnnouncements(module, saveOnCallback(modules, callback, forceRefresh), errorOnCallback(error), forceRefresh));
     }
 
     public void getModuleAssignments(Modules.Module module, final NetworkCallback<Modules.Module> callback, final NetworkErrorCallback error) {
@@ -117,7 +125,7 @@ public class KVV {
     }
 
     public void getModuleAssignments(Modules.Module module, final NetworkCallback<Modules.Module> callback, final NetworkErrorCallback error, boolean forceRefresh) {
-        getModulePart(modules -> modules.getAssignments(module, saveOnCallback(modules, callback), error, forceRefresh));
+        getModulePart(modules -> modules.getAssignments(module, saveOnCallback(modules, callback, forceRefresh), errorOnCallback(error), forceRefresh));
     }
 
     public void getModuleEvents(Modules.Module module, final NetworkCallback<Modules.Module> callback, final NetworkErrorCallback error) {
@@ -125,7 +133,7 @@ public class KVV {
     }
 
     public void getModuleEvents(Modules.Module module, final NetworkCallback<Modules.Module> callback, final NetworkErrorCallback error, boolean forceRefresh) {
-        getModulePart(modules -> modules.getEvents(module, saveOnCallback(modules, callback), error, forceRefresh));
+        getModulePart(modules -> modules.getEvents(module, saveOnCallback(modules, callback, forceRefresh), errorOnCallback(error), forceRefresh));
     }
 
     public void getModuleGradebook(Modules.Module module, final NetworkCallback<Modules.Module> callback, final NetworkErrorCallback error) {
@@ -133,7 +141,7 @@ public class KVV {
     }
 
     public void getModuleGradebook(Modules.Module module, final NetworkCallback<Modules.Module> callback, final NetworkErrorCallback error, boolean forceRefresh) {
-        getModulePart(modules -> modules.getGradebook(module, saveOnCallback(modules, callback), error, forceRefresh));
+        getModulePart(modules -> modules.getGradebook(module, saveOnCallback(modules, callback, forceRefresh), errorOnCallback(error), forceRefresh));
     }
 
 
@@ -149,17 +157,29 @@ public class KVV {
         });
     }
 
-    private<T> NetworkCallback<T> saveOnCallback(KVVModuleList modules, NetworkCallback<T> callback){
+    private<T> NetworkCallback<T> saveOnCallback(KVVModuleList modules, NetworkCallback<T> callback, boolean forceRefresh){
         return (success -> {
             try {
                 modules.saveModulesOffline(this.context);
             } catch (IOException e) {
                 e.printStackTrace();
             }
+            if (forceRefresh)
+                mListener.refreshFailed(false);
             callback.onResponse(success);
         });
     }
 
+    private NetworkErrorCallback errorOnCallback(NetworkErrorCallback errorCallback){
+        return (error -> {
+            if (error.getHttpStatus() == 401 || error.getHttpStatus() == 403)
+                mListener.loginTokenInvalid();
+            else
+                mListener.refreshFailed(true);
+            errorCallback.onError(error);
+        });
+    }
+
     @FunctionalInterface
     interface ModListFunction {
         void apply(KVVModuleList mod);
diff --git a/app/src/main/java/de/sebse/fuplanner/services/KVV/KVVModuleList.java b/app/src/main/java/de/sebse/fuplanner/services/KVV/KVVModuleList.java
index a5c5895..f25c3b7 100644
--- a/app/src/main/java/de/sebse/fuplanner/services/KVV/KVVModuleList.java
+++ b/app/src/main/java/de/sebse/fuplanner/services/KVV/KVVModuleList.java
@@ -375,7 +375,7 @@ public class KVVModuleList extends HTTPService {
 
     private void getGradebookUpgrade(String ID, final NetworkCallback<ArrayList<Gradebook>> callback, final NetworkErrorCallback errorCallback) {
         if (token == null) {
-            errorCallback.onError(new NetworkError(101104, 500, "Currently running in offline mode!"));
+            errorCallback.onError(new NetworkError(101504, 500, "Currently running in offline mode!"));
             return;
         }
         get(String.format("https://kvv.imp.fu-berlin.de/direct/gradebook/site/%s.json", ID ), token.getCookies(), response ->{
diff --git a/app/src/main/java/de/sebse/fuplanner/services/KVV/types/LoginToken.java b/app/src/main/java/de/sebse/fuplanner/services/KVV/types/LoginToken.java
index cd5c537..4f1a090 100644
--- a/app/src/main/java/de/sebse/fuplanner/services/KVV/types/LoginToken.java
+++ b/app/src/main/java/de/sebse/fuplanner/services/KVV/types/LoginToken.java
@@ -16,7 +16,7 @@ import java.util.HashMap;
  */
 
 public class LoginToken implements Serializable {
-    private static final long EASY_LOGIN_TIME_MILLIS = 1000 * 60 * 60 * 3;
+    private static final long EASY_LOGIN_TIME_MILLIS = 1000 * 60 * 60 * 300;
     private static final String FILE_NAME = "LoginTokenSaving";
 
     private final String username;
diff --git a/app/src/main/java/de/sebse/fuplanner/tools/MainAcitivityListener.java b/app/src/main/java/de/sebse/fuplanner/tools/MainAcitivityListener.java
index ea72e1d..84c74a0 100644
--- a/app/src/main/java/de/sebse/fuplanner/tools/MainAcitivityListener.java
+++ b/app/src/main/java/de/sebse/fuplanner/tools/MainAcitivityListener.java
@@ -13,4 +13,8 @@ public interface MainAcitivityListener {
     KVV getKVV();
 
     GoogleAuth getGoogleAuth();
+
+    void loginTokenInvalid();
+
+    void refreshFailed(boolean isFailed);
 }
diff --git a/app/src/main/res/layout/app_bar_main.xml b/app/src/main/res/layout/app_bar_main.xml
index f835238..58e8c9b 100644
--- a/app/src/main/res/layout/app_bar_main.xml
+++ b/app/src/main/res/layout/app_bar_main.xml
@@ -19,6 +19,28 @@
             android:background="@color/colorFUGreen"
             app:popupTheme="@style/AppTheme.PopupOverlay" />
 
+        <TextView
+            android:id="@+id/offline_msg"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:background="@color/colorFURed"
+            android:textColor="@color/colorFUWhite"
+            android:gravity="center"
+            android:textStyle="bold"
+            android:visibility="gone"
+            android:text="@string/offline_mode" />
+
+        <TextView
+            android:id="@+id/no_connection_msg"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:background="@color/colorFUOrange"
+            android:textColor="@color/colorFUWhite"
+            android:gravity="center"
+            android:textStyle="bold"
+            android:visibility="gone"
+            android:text="@string/refresh_failed" />
+
     </android.support.design.widget.AppBarLayout>
 
     <FrameLayout
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index 889bfa4..b692814 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -8,4 +8,6 @@
     <color name="colorFUBlack">#333333</color>
     <color name="colorFURedLight">#f5cccc</color>
     <color name="colorFURedLight2">#cca3a3</color>
+    <color name="colorFURed">#CC0000</color>
+    <color name="colorFUOrange">#FF9900</color>
 </resources>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 70d9a4f..296af8a 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -38,4 +38,6 @@
     <string name="events">Events</string>
     <string name="gradebook">Gradebook</string>
     <string name="Current_percentage">Current Percentage</string>
+    <string name="offline_mode">Offline Mode</string>
+    <string name="refresh_failed">Refresh failed...</string>
 </resources>