diff --git a/HellionChat/Ui/Popout.cs b/HellionChat/Ui/Popout.cs
index 1de5c6c..a2f34f8 100644
--- a/HellionChat/Ui/Popout.cs
+++ b/HellionChat/Ui/Popout.cs
@@ -80,7 +80,10 @@ internal class Popout : Window
         if (!Tab.CanResize)
             Flags |= ImGuiWindowFlags.NoResize;
 
-        if (!ChatLogWindow.PopOutDocked[Idx])
+        // Idx may point past the end if PopOutDocked was resized (e.g., a tab
+        // dropped) between the AddPopOutsToDraw() snapshot and this frame.
+        // Guard the read so we don't index into stale state.
+        if (Idx >= 0 && Idx < ChatLogWindow.PopOutDocked.Count && !ChatLogWindow.PopOutDocked[Idx])
         {
             if (Tab.IndependentOpacity)
             {
@@ -195,7 +198,8 @@ internal class Popout : Window
 
     public override void PostDraw()
     {
-        ChatLogWindow.PopOutDocked[Idx] = ImGui.IsWindowDocked();
+        if (Idx >= 0 && Idx < ChatLogWindow.PopOutDocked.Count)
+            ChatLogWindow.PopOutDocked[Idx] = ImGui.IsWindowDocked();
 
         if (Plugin.Config is { OverrideStyle: true, ChosenStyle: not null })
             StyleModel.GetConfiguredStyles()?.FirstOrDefault(style => style.Name == Plugin.Config.ChosenStyle)?.Pop();
diff --git a/HellionChat/Ui/SettingsTabs/Tabs.cs b/HellionChat/Ui/SettingsTabs/Tabs.cs
index ab46587..8ad2bb0 100755
--- a/HellionChat/Ui/SettingsTabs/Tabs.cs
+++ b/HellionChat/Ui/SettingsTabs/Tabs.cs
@@ -181,28 +181,39 @@ internal sealed class Tabs : ISettingsTab
 
                         ImGui.SameLine();
 
-                        var selectedWorld = worlds.FindIndex(world => world.RowId == tab.TellTarget.World);
-                        if (selectedWorld == -1)
-                            selectedWorld = 0;
-
-                        using (var combo = ImRaii.Combo("###player-world", worlds[selectedWorld].Name.ToString()))
+                        // Guard against an empty worlds list — can happen briefly
+                        // when switching characters or if the datacenter sheet
+                        // has not yet populated. Without the guard the indexed
+                        // access into worlds[selectedWorld] would crash.
+                        if (worlds.Count == 0)
                         {
-                            if (combo.Success)
+                            ImGui.TextDisabled("(no worlds available)");
+                        }
+                        else
+                        {
+                            var selectedWorld = worlds.FindIndex(world => world.RowId == tab.TellTarget.World);
+                            if (selectedWorld == -1)
+                                selectedWorld = 0;
+
+                            using (var combo = ImRaii.Combo("###player-world", worlds[selectedWorld].Name.ToString()))
                             {
-                                var lastDc = worlds.First().DataCenter.RowId;
-                                foreach (var (idx, world) in worlds.Index())
+                                if (combo.Success)
                                 {
-                                    if (ImGui.Selectable(world.Name.ToString(), selectedWorld == idx))
+                                    var lastDc = worlds.First().DataCenter.RowId;
+                                    foreach (var (idx, world) in worlds.Index())
                                     {
-                                        selectedWorld = idx;
-                                        tab.TellTarget.World = worlds[selectedWorld].RowId;
+                                        if (ImGui.Selectable(world.Name.ToString(), selectedWorld == idx))
+                                        {
+                                            selectedWorld = idx;
+                                            tab.TellTarget.World = worlds[selectedWorld].RowId;
+                                        }
+
+                                        if (lastDc == world.DataCenter.RowId)
+                                            continue;
+
+                                        lastDc = world.DataCenter.RowId;
+                                        ImGui.Separator();
                                     }
-
-                                    if (lastDc == world.DataCenter.RowId)
-                                        continue;
-
-                                    lastDc = world.DataCenter.RowId;
-                                    ImGui.Separator();
                                 }
                             }
                         }