--- a/dialogs/ProjectDialog.py	Thu Sep 02 21:36:29 2021 +0200
+++ b/dialogs/ProjectDialog.py	Thu Sep 02 22:18:14 2021 +0200
@@ -42,12 +42,11 @@
 
         self.ProjectProperties = ProjectPropertiesPanel(
             self, enable_required=enable_required, scrolling=False)
-        main_sizer.AddWindow(self.ProjectProperties, flag=wx.GROW)
+        main_sizer.Add(self.ProjectProperties, flag=wx.GROW)
 
         self.ButtonSizer = self.CreateButtonSizer(wx.OK | wx.CANCEL | wx.CENTRE)
-        self.Bind(wx.EVT_BUTTON, self.OnOK,
-                  self.ButtonSizer.GetAffirmativeButton())
-        main_sizer.AddSizer(self.ButtonSizer, border=20,
+        self.Bind(wx.EVT_BUTTON, self.OnOK, id=self.GetAffirmativeId())
+        main_sizer.Add(self.ButtonSizer, border=20,
                             flag=wx.ALIGN_RIGHT | wx.BOTTOM | wx.LEFT | wx.RIGHT)
 
         self.SetSizer(main_sizer)