diff --git a/app/src/main/java/org/secuso/privacyfriendlysudoku/ui/CreateSudokuActivity.java b/app/src/main/java/org/secuso/privacyfriendlysudoku/ui/CreateSudokuActivity.java
index 9b3df36..7d69953 100644
--- a/app/src/main/java/org/secuso/privacyfriendlysudoku/ui/CreateSudokuActivity.java
+++ b/app/src/main/java/org/secuso/privacyfriendlysudoku/ui/CreateSudokuActivity.java
@@ -26,11 +26,6 @@ import org.secuso.privacyfriendlysudoku.ui.view.CreateSudokuSpecialButtonLayout;
 import org.secuso.privacyfriendlysudoku.ui.view.R;
 import org.secuso.privacyfriendlysudoku.ui.view.SudokuFieldLayout;
 import org.secuso.privacyfriendlysudoku.ui.view.SudokuKeyboardLayout;
-import org.secuso.privacyfriendlysudoku.ui.view.SudokuSpecialButtonLayout;
-
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.util.LinkedList;
 
 public class CreateSudokuActivity extends BaseActivity implements IFinalizeDialogFragmentListener {
 
@@ -45,28 +40,18 @@ public class CreateSudokuActivity extends BaseActivity implements IFinalizeDialo
         super.onCreate(savedInstanceState);
         SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
 
-        if (sharedPref.getBoolean("pref_dark_mode_setting", false )) {
-            AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
-        } else {
-            AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
-        }
-
         if(sharedPref.getBoolean("pref_keep_screen_on", true)) {
             getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
         }
 
         gameController = new GameController(sharedPref, getApplicationContext());
 
-        if(sharedPref.getBoolean("pref_keep_screen_on", true)) {
-            getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
-        }
-
         Bundle extras = getIntent().getExtras();
         GameType gameType = GameType.valueOf(extras.getString("gameType", GameType.Default_9x9.name()));
         int sectionSize = gameType.getSize();
         int boardSize = sectionSize * sectionSize;
 
-        GameInfoContainer container = new GameInfoContainer(0, GameDifficulty.Unspecified,
+        GameInfoContainer container = new GameInfoContainer(0, GameDifficulty.Moderate,
                 gameType, new int [boardSize], new int [boardSize], new boolean [boardSize][sectionSize]);
         gameController.loadLevel(container);
 
@@ -126,16 +111,20 @@ public class CreateSudokuActivity extends BaseActivity implements IFinalizeDialo
         GameType gameType = gameController.getGameType();
         int boardSize = gameType.getSize() * gameType.getSize();
         String boardContent = gameController.getCodeOfField();
+
         GameInfoContainer container = new GameInfoContainer(0, GameDifficulty.Unspecified,
                 gameType, new int [boardSize], new int [boardSize], new boolean [boardSize][gameType.getSize()]);
         container.parseFixedValues(boardContent);
+        //gameController.loadLevel(container);
 
         QQWing verifier = new QQWing(gameType, GameDifficulty.Unspecified);
         verifier.setRecordHistory(true);
         verifier.setPuzzle(container.getFixedValues());
-        boolean solvable = verifier.solve();
+        verifier.solve();
 
-        if(solvable) {
+        boolean distinctlySolvable = verifier.hasUniqueSolution();
+
+        if(distinctlySolvable) {
             Toast.makeText(CreateSudokuActivity.this, R.string.finished_verifying_custom_sudoku_toast, Toast.LENGTH_LONG).show();
             final Intent intent = new Intent(this, GameActivity.class);
             intent.setData(Uri.parse(GameActivity.URL_SCHEME_WITHOUT_HOST + "://" + boardContent));
diff --git a/app/src/main/java/org/secuso/privacyfriendlysudoku/ui/GameActivity.java b/app/src/main/java/org/secuso/privacyfriendlysudoku/ui/GameActivity.java
index ad301dc..79237e0 100644
--- a/app/src/main/java/org/secuso/privacyfriendlysudoku/ui/GameActivity.java
+++ b/app/src/main/java/org/secuso/privacyfriendlysudoku/ui/GameActivity.java
@@ -147,7 +147,9 @@ public class GameActivity extends BaseActivity implements NavigationView.OnNavig
                     difficultyCheck = new QQWing(container.getGameType(), GameDifficulty.Unspecified);
                     difficultyCheck.setRecordHistory(true);
                     difficultyCheck.setPuzzle(container.getFixedValues());
-                    startGame = difficultyCheck.solve();
+                    difficultyCheck.solve();
+
+                    startGame = difficultyCheck.hasUniqueSolution();
                     container.parseDifficulty(difficultyCheck.getDifficulty().toString());
 
                 } catch (IllegalArgumentException e) {
diff --git a/app/src/main/res/menu/menu_drawer_main.xml b/app/src/main/res/menu/menu_drawer_main.xml
index f8e8a43..e996b31 100644
--- a/app/src/main/res/menu/menu_drawer_main.xml
+++ b/app/src/main/res/menu/menu_drawer_main.xml
@@ -6,7 +6,9 @@
         <item android:id="@+id/nav_newgame_main" android:icon="@drawable/ic_menu_home"
             android:title="@string/menu_main" />
         <item android:id="@+id/nav_dailySudoku_main" android:icon="@drawable/ic_menu_daily_sudoku"
-            android:title="Daily Sudoku" /> 
+            android:title="@string/menu_daily_sudoku" />
+        <item android:id="@+id/nav_import_sudoku" android:icon="@android:drawable/ic_input_get"
+            android:title="@string/menu_import_custom_sudoku"/>
         <item android:id="@+id/nav_highscore_main" android:icon="@android:drawable/ic_menu_myplaces"
             android:title="@string/menu_highscore" />
         <item android:id="@+id/menu_tutorial_main" android:icon="@drawable/ic_school_black_24dp"
diff --git a/app/src/main/res/values-de/strings.xml b/app/src/main/res/values-de/strings.xml
index 790e9e0..bf7fd65 100644
--- a/app/src/main/res/values-de/strings.xml
+++ b/app/src/main/res/values-de/strings.xml
@@ -106,10 +106,12 @@
     <string name="menu_tutorial">Tutorial</string>
 
     <!-- ### DailySudokuActivity ###-->
+    <string name="menu_daily_sudoku">Sudoku des Tages</string>
     <string name="finished_daily_sudoku">Du hast das Sudoku des Tages bereits gelöst.</string>
     <string name="daily_number_of_hints">Benutzte Hinweise</string>
 
     <!-- ### Create custome sudoku ###-->
+    <string name="menu_import_custom_sudoku">Sudoku importieren</string>
     <string name="finalize_custom_sudoku_dialog">Möchtest du dieses Sudoku fertigstellen?</string>
     <string name="verify_custom_sudoku_process_toast">Verifiziere Level&#8230;</string>
     <string name="finished_verifying_custom_sudoku_toast">Verifizierung abgeschlossen!</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 0ccd6a2..f40a3ff 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -162,11 +162,13 @@
     <string name="menu_tutorial">Tutorial</string>
 
     <!-- ### DailySudokuActivity ###-->
+    <string name="menu_daily_sudoku">Daily Sudoku</string>
     <string name="finished_daily_sudoku">You have already solved the sudoku of the day</string>
     <string name="daily_number_of_hints">Used hints</string>
     <string name="number_of_completed_games">Completed games</string>
 
     <!-- ### Create custome sudoku ###-->
+    <string name="menu_import_custom_sudoku">Import Sudoku</string>
     <string name="finalize_custom_sudoku_dialog">Do you wish to finalize this sudoku?</string>
     <string name="verify_custom_sudoku_process_toast">Verifying&#8230;</string>
     <string name="finished_verifying_custom_sudoku_toast">Done verifying!</string>