diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index eb5ede0a5..795aac898 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -1626,7 +1626,7 @@ void GCode::_do_export(Print& print, FILE* file, ThumbnailsGeneratorCallback thu
     _write_format(file, "; estimated printing time (normal mode) = %s\n", m_normal_time_estimator.get_time_dhms().c_str());
     if (m_silent_time_estimator_enabled)
         _write_format(file, "; estimated printing time (silent mode) = %s\n", m_silent_time_estimator.get_time_dhms().c_str());
-#endif // !ENABLE_GCODE_VIEWER
+#endif // ENABLE_GCODE_VIEWER
 
     // Append full config.
     _write(file, "\n");
diff --git a/src/slic3r/GUI/MainFrame.cpp b/src/slic3r/GUI/MainFrame.cpp
index 794da80b2..6c3f2a4ea 100644
--- a/src/slic3r/GUI/MainFrame.cpp
+++ b/src/slic3r/GUI/MainFrame.cpp
@@ -1006,7 +1006,9 @@ void MainFrame::init_menubar()
         fileMenu->AppendSeparator();
         append_menu_item(fileMenu, wxID_ANY, _L("&G-code preview"), _L("Switch to G-code preview mode"),
             [this](wxCommandEvent&) {
-                if (m_plater->model().objects.empty() || wxMessageDialog((wxWindow*)this, _L("Switching to G-code preview mode will remove all objects, continue?"), wxString(SLIC3R_APP_NAME) + " - " + _L("Switch to G-code preview mode"), wxYES_NO | wxCANCEL | wxYES_DEFAULT | wxCENTRE).ShowModal() == wxID_YES)
+                if (m_plater->model().objects.empty() ||
+                    wxMessageDialog((wxWindow*)this, _L("Switching to G-code preview mode will remove all objects, continue?"),
+                        wxString(SLIC3R_APP_NAME) + " - " + _L("Switch to G-code preview mode"), wxYES_NO | wxCANCEL | wxYES_DEFAULT | wxICON_QUESTION | wxCENTRE).ShowModal() == wxID_YES)
                     set_mode(EMode::GCodeViewer);
             }, "", nullptr,
             [this]() { return m_plater != nullptr && m_plater->printer_technology() != ptSLA; }, this);
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 79f8b5ad5..67b531eae 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -1362,25 +1362,43 @@ const std::regex PlaterDropTarget::pattern_gcode_drop(".*[.](gcode)", std::regex
 bool PlaterDropTarget::OnDropFiles(wxCoord x, wxCoord y, const wxArrayString &filenames)
 {
     std::vector<fs::path> paths;
-#if ENABLE_GCODE_VIEWER
-    if (wxGetApp().mainframe->get_mode() == MainFrame::EMode::GCodeViewer) {
-        for (const auto& filename : filenames) {
-            fs::path path(into_path(filename));
-            if (std::regex_match(path.string(), pattern_gcode_drop))
-                paths.push_back(std::move(path));
-        }
 
-        if (paths.size() > 1) {
-            wxMessageDialog((wxWindow*)plater, _L("Only one gcode file at a time can be opened."), wxString(SLIC3R_APP_NAME) + " - " + _L("Open G-code file"), wxCLOSE | wxICON_WARNING | wxCENTRE).ShowModal();
-            return false;
-        }
-        else if (paths.size() == 1) {
+#if ENABLE_GCODE_VIEWER
+    // gcode section
+    for (const auto& filename : filenames) {
+        fs::path path(into_path(filename));
+        if (std::regex_match(path.string(), pattern_gcode_drop))
+            paths.push_back(std::move(path));
+    }
+
+    if (paths.size() > 1) {
+        wxMessageDialog((wxWindow*)plater, _L("You can open only one .gcode file at a time."),
+            wxString(SLIC3R_APP_NAME) + " - " + _L("Open G-code file"), wxCLOSE | wxICON_WARNING | wxCENTRE).ShowModal();
+        return false;
+    }
+    else if (paths.size() == 1) {
+        if (wxGetApp().mainframe->get_mode() == MainFrame::EMode::GCodeViewer) {
             plater->load_gcode(from_path(paths.front()));
             return true;
         }
+        else {
+            if (wxMessageDialog((wxWindow*)plater, _L("Do you want to switch to G-code preview ?"),
+                wxString(SLIC3R_APP_NAME) + " - " + _L("Open G-code file"), wxYES_NO | wxCANCEL | wxICON_QUESTION | wxYES_DEFAULT | wxCENTRE).ShowModal() == wxID_YES) {
+
+                if (plater->model().objects.empty() ||
+                    wxMessageDialog((wxWindow*)plater, _L("Switching to G-code preview mode will remove all objects, continue?"),
+                        wxString(SLIC3R_APP_NAME) + " - " + _L("Switch to G-code preview mode"), wxYES_NO | wxCANCEL | wxICON_QUESTION | wxYES_DEFAULT | wxCENTRE).ShowModal() == wxID_YES) {
+                    wxGetApp().mainframe->set_mode(MainFrame::EMode::GCodeViewer);
+                    plater->load_gcode(from_path(paths.front()));
+                    return true;
+                }
+            }
+            return false;
+        }
     }
 #endif // ENABLE_GCODE_VIEWER
 
+    // model section
     for (const auto &filename : filenames) {
         fs::path path(into_path(filename));
         if (std::regex_match(path.string(), pattern_drop))