diff --git a/sync_manager.py b/sync_manager.py
index 6d1dbf48..91960d3f 100644
--- a/sync_manager.py
+++ b/sync_manager.py
@@ -101,23 +101,29 @@ class SyncManager:
         self.logger.info("Lade bestehende Daten aus dem Google Sheet...")
         try:
             all_data_with_headers = self.sheet_handler.get_all_data_with_headers()
-            
             if not all_data_with_headers or len(all_data_with_headers) < self.sheet_handler._header_rows:
-                self.gsheet_df = pd.DataFrame(columns=COLUMN_ORDER).fillna('')
+                self.gsheet_df = pd.DataFrame(columns=COLUMN_ORDER)
             else:
                 actual_header = all_data_with_headers[self.sheet_handler._header_rows - 1]
-                data_rows_raw = all_data_with_headers[self.sheet_handler._header_rows:]
+                data_rows = all_data_with_headers[self.sheet_handler._header_rows:]
                 
-                # --- HOLZHAMMER-METHODE: JEDE ZELLE ZU STRING KONVERTIEREN ---
-                data_rows_as_string = [[str(cell) for cell in row] for row in data_rows_raw]
-
-                temp_df = pd.DataFrame(data_rows_as_string, columns=actual_header)
+                # --- FINALER DATAFRAME-ERSTELLUNGS-FIX ---
+                # Wir erstellen das DataFrame aus einem Dictionary, das ist am robustesten.
+                data_dict = {header_col: [] for header_col in actual_header}
+                for row in data_rows:
+                    for i, header_col in enumerate(actual_header):
+                        # Fülle fehlende Werte auf, wenn eine Zeile zu kurz ist
+                        value = row[i] if i < len(row) else ''
+                        data_dict[header_col].append(str(value)) # Sofort zu String konvertieren
+                
+                temp_df = pd.DataFrame(data_dict)
                 
                 for col_name in COLUMN_ORDER:
                     if col_name not in temp_df.columns:
                         temp_df[col_name] = ''
                 
-                self.gsheet_df = temp_df[COLUMN_ORDER].fillna('')
+                self.gsheet_df = temp_df[COLUMN_ORDER]
+
         except Exception as e:
             self.logger.critical(f"Fehler beim Laden/Umwandeln der GSheet-Daten: {e}", exc_info=True)
             return False