CURA-5090 Remove layer view data after clearing buildplate

plugins/SimulationView/SimulationView.py

@@ -158,7 +158,9 @@ class SimulationView(View):
         return self._nozzle_node
 
     def _onSceneChanged(self, node):
-        if node.getMeshData() is not None:
+        if node.getMeshData() is None:
+            self.resetLayerData()
+        else:
             self.setActivity(False)
             self.calculateMaxLayers()
             self.calculateMaxPathsOnLayer(self._current_layer_num)