* Small square rendered next to Close button on KryptonForm when usin…

Documents/Changelog/Changelog.md

@@ -45,6 +45,7 @@
 
 ## 2026-11-xx - Build 2611 (V110 Nightly) - November 2026
 
+* Resolved [#3183](https://github.com/Krypton-Suite/Standard-Toolkit/issues/3183), Small square rendered next to Close button on KryptonForm when using a custom theme
 * Resolved [#3249](https://github.com/Krypton-Suite/Standard-Toolkit/issues/3249), `KryptonForm` shows an extra border on the secondary monitor when maximized
 * Resolved [#3013](https://github.com/Krypton-Suite/Standard-Toolkit/issues/3013), Maximized form's size exceeds the screen's working area
 * Resolved [#3164](https://github.com/Krypton-Suite/Standard-Toolkit/issues/3164), Font property values are being serialized depending of the current culture in exported XML theme file

Source/Krypton Components/Krypton.Toolkit/Controls Toolkit/KryptonCustomPaletteBase.cs

@@ -3124,6 +3124,14 @@ private void ImportFromXmlDocument([DisallowNull] XmlDocument doc)
                 SetPaletteName(root.GetAttribute("Name"));
             }
 
+            // Populate missing palette values from the base palette first.
+            //
+            // Some theme XML files intentionally omit certain button/header metrics and
+            // drawing settings. Without an initial populate step, those omitted values can
+            // remain at placeholder defaults and cause small rendering artifacts in the
+            // KryptonForm caption chrome (e.g. near the system Close button).
+            PopulateFromBaseOperation(null);
+
             // Grab the properties and images elements
             var props = root.SelectSingleNode(nameof(Properties)) as XmlElement;
             var images = root.SelectSingleNode(nameof(Images)) as XmlElement;