Fix critical when setting (sub)title

2 files changed, 3 insertions, 3 deletions

diff --git a/main/src/ui/conversation_view_controller.vala b/main/src/ui/conversation_view_controller.vala
index bf53deb4..2b073e2d 100644
--- a/main/src/ui/conversation_view_controller.vala
+++ b/main/src/ui/conversation_view_controller.vala
@@ -141,8 +141,8 @@ public class ConversationViewController : Object {
     }
 
     public void unset_conversation() {
-        main_window.conversation_window_title.title = null;
-        main_window.conversation_window_title.subtitle = null;
+        main_window.conversation_window_title.title = "";
+        main_window.conversation_window_title.subtitle = "";
     }
 
     private async void update_file_upload_status() {
diff --git a/main/src/ui/util/preference_group.vala b/main/src/ui/util/preference_group.vala
index ab2229f8..c2b96f41 100644
--- a/main/src/ui/util/preference_group.vala
+++ b/main/src/ui/util/preference_group.vala
@@ -98,7 +98,7 @@ namespace Dino.Ui.Util {
 
         var toggle_view_model = preferences_row as ViewModel.PreferencesRow.Toggle;
         if (toggle_view_model != null) {
-            var view = new Adw.ActionRow() { title = toggle_view_model.title, subtitle = toggle_view_model.subtitle };
+            var view = new Adw.ActionRow() { title = toggle_view_model.title, subtitle = toggle_view_model.subtitle ?? "" };
             var toggle = new Switch() { valign = Align.CENTER };
             view.activatable_widget = toggle;
             view.add_suffix(toggle);