diff --git a/Liner/Liner/MapsCollection.cs b/Liner/Liner/MapsCollection.cs
index c3157f7..80106d5 100644
--- a/Liner/Liner/MapsCollection.cs
+++ b/Liner/Liner/MapsCollection.cs
@@ -68,8 +68,8 @@ namespace Liner
             }
             using (StreamReader sr = new(filename))
             {
-                string str = sr.ReadLine();
-                if (!str.Contains("MapsCollection"))
+                string str = "";
+                if ((str = sr.ReadLine()) == null || !str.Contains("MapsCollection"))
                 {
                     return false;
                 }