assert shutter file exists

csst_common/data_manager.py

@@ -580,16 +580,17 @@ class CsstMsDataManager:
 
     def get_shutter(self, detector=6):
         """ get flat data """
-        if self.custom_flat is None:
-            return os.path.join(
+        fp = os.path.join(
             self.path_aux,
             "C6.2_ref_mbi",
             "CSST_MSC_MS_SHUTTER_{:02d}_{:04d}.fits".format(
                 detector, 1 if self.ref_version is None else self.ref_version
             )
         )
+        if not os.path.exists(fp):
+            raise FileNotFoundError(fp)
         else:
-            return self.custom_flat.format("flat", detector)
+            return fp
 
     def get_axeconf(self):
         return os.path.join(self.path_aux, "axeconf")  # "/home/csstpipeline/L1Pipeline/aux/axeconf"