diff --git a/sohstationviewer/controller/util.py b/sohstationviewer/controller/util.py
index 5b5ee8513e6e3028a5a739037b1e505483f85de4..04fd4408d5b700c70fcbd8a87bcbd5ca6f935f14 100644
--- a/sohstationviewer/controller/util.py
+++ b/sohstationviewer/controller/util.py
@@ -288,6 +288,8 @@ def rt130_find_cf_dass(root_dir: str) -> Dict[str, List[Path]]:
         root_dir += os.sep
     day_dirs = os.listdir(root_dir)
     for day_dir in day_dirs:
+        if day_dir.startswith('.'):
+            continue
         if len(day_dir) == 7 and day_dir.isdigit():
             # check for directory with format YYYYDOY: 7 digits
             try:
@@ -301,6 +303,8 @@ def rt130_find_cf_dass(root_dir: str) -> Dict[str, List[Path]]:
                     if das_dir not in das_dict.keys():
                         das_dict[das_dir] = []
                     das_dict[das_dir].append(das_path)
+        else:
+            return {}
     return das_dict