diff --git a/plugins/CuraEngineBackend/CuraEngineBackend.py b/plugins/CuraEngineBackend/CuraEngineBackend.py
index 9e37fa9049..40729eb48b 100644
--- a/plugins/CuraEngineBackend/CuraEngineBackend.py
+++ b/plugins/CuraEngineBackend/CuraEngineBackend.py
@@ -127,13 +127,15 @@ class CuraEngineBackend(Backend):
 
     ##  Perform a slice of the scene.
     def slice(self):
+        if not self._enabled or not self._global_container_stack: #We shouldn't be slicing.
+            # try again in a short time
+            self._change_timer.start()
+            return
+
         self.printDurationMessage.emit(0, [0])
 
         self._stored_layer_data = []
 
-        if not self._enabled or not self._global_container_stack: #We shouldn't be slicing.
-            return
-
         if self._slicing: #We were already slicing. Stop the old job.
             self._terminate()
 
diff --git a/resources/materials/generic_pla.xml.fdm_material b/resources/materials/generic_pla.xml.fdm_material
index 2f8fa165cf..40432d5849 100644
--- a/resources/materials/generic_pla.xml.fdm_material
+++ b/resources/materials/generic_pla.xml.fdm_material
@@ -9,7 +9,7 @@ Generic PLA profile. Serves as an example file, data in this file is not correct
             <material>PLA</material>
             <color>Generic</color>
         </name>
-        <GUID>86a89ceb-4159-47f6-ab97-e9953803d70f</GUID>
+        <GUID>506c9f0d-e3aa-4bd4-b2d2-23e2425b1aa9</GUID>
         <version>0</version>
         <color_code>#00FF00</color_code>
     </metadata>