diff --git a/blight-editor/src/main/java/de/blight/editor/EditorApp.java b/blight-editor/src/main/java/de/blight/editor/EditorApp.java
index ee60772..0a71d49 100644
--- a/blight-editor/src/main/java/de/blight/editor/EditorApp.java
+++ b/blight-editor/src/main/java/de/blight/editor/EditorApp.java
@@ -360,7 +360,7 @@ public class EditorApp extends Application {
             input, jmeApp, () -> stage,
             this::setStatus, this::setCenterView,
             root::setRight, node -> topBar.getChildren().set(1, node),
-            () -> centerStack, ASSET_ROOT, this::switchToWorldEditor, registry
+            () -> worldViewport, ASSET_ROOT, this::switchToWorldEditor, registry
         );
         vegController         = new de.blight.editor.toolset.vegetation.VegetationController(toolCtx);
         ezTreeController      = new de.blight.editor.toolset.eztree.EzTreeController(toolCtx);
@@ -770,9 +770,10 @@ public class EditorApp extends Application {
     }
 
     private void switchToWorldEditor() {
-        boolean wasObjEditor        = "objecteditor".equals(currentTool);
-        boolean wasModelEditor      = "modeleditor".equals(currentTool);
+        boolean wasObjEditor        = "objecteditor".equals(registry.activeToolId()) || "objecteditor".equals(currentTool);
+        boolean wasModelEditor      = "modeleditor".equals(registry.activeToolId())  || "modeleditor".equals(currentTool);
         boolean wasThumbnailManager = "thumbnailmanager".equals(currentTool);
+        registry.deactivateAll();
         currentTool = "world";
         if (jmeApp != null) jmeApp.setRenderThrottled(false);
         root.setLeft(null);   // ggf. gesetzten Content-Tree entfernen
@@ -3508,7 +3509,7 @@ public class EditorApp extends Application {
             }
 
             if (cat == modelsNode) {
-                if ("modeleditor".equals(currentTool) && relPath.endsWith(".j3o")) {
+                if ("modeleditor".equals(registry.activeToolId()) && relPath.endsWith(".j3o")) {
                     modelEditorController.openModelEditor(relPath, p);
                     return;
                 }
@@ -4870,7 +4871,7 @@ public class EditorApp extends Application {
     /** Gibt zurück, ob das aktive Tool den aufgeklappten Zustand des Asset-Baums behalten soll. */
     private boolean shouldPreserveExpansion() {
         return "vegetation".equals(currentTool) || "eztree".equals(currentTool)
-                || "objecteditor".equals(currentTool) || "modeleditor".equals(currentTool)
+                || "objecteditor".equals(registry.activeToolId()) || "modeleditor".equals(registry.activeToolId())
                 || ("world".equals(currentTool)
                     && (input.activeLayer == SharedInput.LAYER_OBJECTS
                         || input.activeLayer == SharedInput.LAYER_OBJECTS_EDIT));
diff --git a/blight-editor/src/main/java/de/blight/editor/ToolRegistry.java b/blight-editor/src/main/java/de/blight/editor/ToolRegistry.java
index ab12846..71eafc1 100644
--- a/blight-editor/src/main/java/de/blight/editor/ToolRegistry.java
+++ b/blight-editor/src/main/java/de/blight/editor/ToolRegistry.java
@@ -36,6 +36,14 @@ public class ToolRegistry {
         return active != null ? active.toolId() : "";
     }
 
+    /** Deaktiviert das aktive Werkzeug und setzt den Zustand auf "kein Tool aktiv". */
+    public void deactivateAll() {
+        if (active != null) {
+            active.deactivate();
+            active = null;
+        }
+    }
+
     /**
      * Muss jeden JavaFX-AnimationTimer-Frame aufgerufen werden.
      * Delegiert an {@link ToolController#onFrame()} des aktiven Werkzeugs.
diff --git a/blight-editor/src/main/java/de/blight/editor/toolset/model/ModelEditorController.java b/blight-editor/src/main/java/de/blight/editor/toolset/model/ModelEditorController.java
index 8128e2f..3765944 100644
--- a/blight-editor/src/main/java/de/blight/editor/toolset/model/ModelEditorController.java
+++ b/blight-editor/src/main/java/de/blight/editor/toolset/model/ModelEditorController.java
@@ -267,7 +267,11 @@ public class ModelEditorController implements ToolController {
     public void openModelEditor(String relPath, Path absolutePath) {
         this.pendingRelPath = relPath;
         this.pendingAbsPath = absolutePath;
-        ctx.registry().activate(this);
+        if (ctx.registry().getActive() == this) {
+            activate();
+        } else {
+            ctx.registry().activate(this);
+        }
     }
 
     /** Öffnet den Datei-Dialog für den Modell-Import. */