diff --git a/flatlaf-theme-editor/src/main/java/com/formdev/flatlaf/themeeditor/FlatThemeFileEditor.java b/flatlaf-theme-editor/src/main/java/com/formdev/flatlaf/themeeditor/FlatThemeFileEditor.java
index c3b53a64..03c35552 100644
--- a/flatlaf-theme-editor/src/main/java/com/formdev/flatlaf/themeeditor/FlatThemeFileEditor.java
+++ b/flatlaf-theme-editor/src/main/java/com/formdev/flatlaf/themeeditor/FlatThemeFileEditor.java
@@ -280,7 +280,9 @@ class FlatThemeFileEditor
 		for( File file : getPropertiesFiles( dir ) )
 			openFile( file, file.getName().equals( recentFile ) );
 
-		activateEditor();
+		SwingUtilities.invokeLater( () -> {
+			activateEditor();
+		} );
 		saveState();
 		enableDisableActions();