diff --git a/VRCMelonAssistant/Classes/Utils.cs b/VRCMelonAssistant/Classes/Utils.cs
index c7baaec..b95f901 100644
--- a/VRCMelonAssistant/Classes/Utils.cs
+++ b/VRCMelonAssistant/Classes/Utils.cs
@@ -153,7 +153,7 @@ namespace VRCMelonAssistant
             Properties.Settings.Default.InstallFolder = directory;
             Properties.Settings.Default.StoreType = store;
             Properties.Settings.Default.Save();
-            MainWindow.Instance.MarkModsPageForRefresh();
+            MainWindow.Instance?.MarkModsPageForRefresh();
             return directory;
         }