diff --git a/webui/generator/generator.py b/webui/generator/generator.py
index ff6db7a..118f28d 100644
--- a/webui/generator/generator.py
+++ b/webui/generator/generator.py
@@ -225,7 +225,7 @@ def read_generation_settings(self) -> tuple[mfs.Map, str]:
             lat, lon = self.main_settings.lat_lon
         except ValueError:
             st.error("Invalid latitude and longitude!")
-            return
+            return None, None
 
         # Prepare a tuple with the coordinates of the center point of the map.
         coordinates = (lat, lon)
@@ -294,6 +294,10 @@ def generate_map(self) -> None:
 
         mp, session_name = self.read_generation_settings()
 
+        if mp is None or session_name is None:
+            st.error("Incorrect settings were provided.")
+            return
+
         if self.public:
             add_to_queue(session_name)
             for position in wait_in_queue(session_name):