diff --git a/src/run_modules/pre_processing.py b/src/run_modules/pre_processing.py
index 3263f5c4562eeac321c7ce621df551fdf6373ba0..1d014c9e6f4fc0a9168c4d3d31b1141c39fff2a1 100644
--- a/src/run_modules/pre_processing.py
+++ b/src/run_modules/pre_processing.py
@@ -137,9 +137,10 @@ class PreProcessing(RunEnvironment):
         for station in all_stations:
             t_inner.run()
             try:
-                # (history, label) = data_gen[station]
                 data = data_gen.get_data_generator(key=station, load_local_tmp_storage=load_tmp,
                                                    save_local_tmp_storage=save_tmp)
+                if data.history is None:
+                    raise AttributeError
                 valid_stations.append(station)
                 logging.debug(f'{station}: history_shape = {data.history.transpose("datetime", "window", "Stations", "variables").shape}')
                 logging.debug(f"{station}: loading time = {t_inner}")