diff --git a/src/slic3r/GUI/GUI_App.cpp b/src/slic3r/GUI/GUI_App.cpp
index 23f79c65f..09dcf875b 100644
--- a/src/slic3r/GUI/GUI_App.cpp
+++ b/src/slic3r/GUI/GUI_App.cpp
@@ -634,7 +634,6 @@ bool GUI_App::OnInit()
 
 bool GUI_App::on_init_inner()
 {
-    TaskTimer timer("on_init");
     // Verify resources path
     const wxString resources_dir = from_u8(Slic3r::resources_dir());
     wxCHECK_MSG(wxDirExists(resources_dir), false,
@@ -759,8 +758,6 @@ bool GUI_App::on_init_inner()
 #endif // ENABLE_GCODE_VIEWER
         scrn->SetText(_L("Creating settings tabs..."));
 
-    TaskTimer timer2("Creating settings tabs");
-
     mainframe = new MainFrame();
     // hide settings tabs after first Layout
     mainframe->select_tab(size_t(0));
diff --git a/src/slic3r/GUI/MainFrame.cpp b/src/slic3r/GUI/MainFrame.cpp
index 4ecd36c7f..6ee496052 100644
--- a/src/slic3r/GUI/MainFrame.cpp
+++ b/src/slic3r/GUI/MainFrame.cpp
@@ -668,8 +668,6 @@ void MainFrame::add_created_tab(Tab* panel)
 
 bool MainFrame::is_active_and_shown_tab(Tab* tab)
 {
-    if (!this)
-        return false;
     int page_id = m_tabpanel->FindPage(tab);
 
     if (m_tabpanel->GetSelection() != page_id)
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index 3517381cf..924f3c8bb 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -3471,10 +3471,8 @@ bool Tab::tree_sel_change_delayed()
         //for (auto& el : m_pages)
         //    el.get()->Hide();
 
-        if (wxGetApp().mainframe->is_active_and_shown_tab(this)) {
+        if (wxGetApp().mainframe!=nullptr && wxGetApp().mainframe->is_active_and_shown_tab(this))
             activate_selected_page(throw_if_canceled);
-    //        m_active_page->Show();
-        }
 
         #ifdef __linux__
             no_updates.reset(nullptr);