Prevent to create new readonly model

tryton/gui/window/view_form/screen/screen.py

@@ -353,6 +353,8 @@ class Screen(SignalEvent):
         return False
 
     def new(self, default=True, context=None):
+        if self.models.readonly:
+            return
         if context is None:
             context = {}
         if self.current_view and ((self.current_view.view_type == 'tree' \