diff --git a/src/slic3r/GUI/GUI_ObjectList.cpp b/src/slic3r/GUI/GUI_ObjectList.cpp
index 096836f23..c99d9090c 100644
--- a/src/slic3r/GUI/GUI_ObjectList.cpp
+++ b/src/slic3r/GUI/GUI_ObjectList.cpp
@@ -4030,17 +4030,12 @@ void ObjectList::simplify()
 
     // Do not simplify when a gizmo is open. There might be issues with updates
     // and what is worse, the snapshot time would refer to the internal stack.
-    auto current_type = gizmos_mgr.get_current_type();
-    if (current_type == GLGizmosManager::Simplify) {
+    if (! gizmos_mgr.check_gizmos_closed_except(GLGizmosManager::EType::Simplify))
+        return;
+
+    if (gizmos_mgr.get_current_type() == GLGizmosManager::Simplify) {
         // close first
         gizmos_mgr.open_gizmo(GLGizmosManager::EType::Simplify);
-    }else if (current_type != GLGizmosManager::Undefined) {
-        plater->get_notification_manager()->push_notification(
-            NotificationType::CustomSupportsAndSeamRemovedAfterRepair,
-            NotificationManager::NotificationLevel::RegularNotification,
-            _u8L("ERROR: Please close all manipulators available from "
-                 "the left toolbar before start simplify the mesh."));
-        return;
     }
     gizmos_mgr.open_gizmo(GLGizmosManager::EType::Simplify);
 }
diff --git a/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp b/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
index dfe6de746..93eba3042 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
@@ -164,10 +164,8 @@ void GLGizmosManager::refresh_on_off_state()
         return;
 
     if (m_current != Undefined
-    && ! m_gizmos[m_current]->is_activable()) {
-        activate_gizmo(Undefined);
+    && ! m_gizmos[m_current]->is_activable() && activate_gizmo(Undefined))
         update_data();
-    }
 }
 
 void GLGizmosManager::reset_all_states()
@@ -182,14 +180,28 @@ void GLGizmosManager::reset_all_states()
 bool GLGizmosManager::open_gizmo(EType type)
 {
     int idx = int(type);
-    if (m_gizmos[idx]->is_activable()) {
-        activate_gizmo(m_current == idx ? Undefined : (EType)idx);
+    if (m_gizmos[idx]->is_activable()
+     && activate_gizmo(m_current == idx ? Undefined : (EType)idx)) {
         update_data();
         return true;
     }
     return false;
 }
 
+
+bool GLGizmosManager::check_gizmos_closed_except(EType type) const
+{
+    if (get_current_type() != type && get_current_type() != Undefined) {
+        wxGetApp().plater()->get_notification_manager()->push_notification(
+                    NotificationType::CustomSupportsAndSeamRemovedAfterRepair,
+                    NotificationManager::NotificationLevel::RegularNotification,
+                    _u8L("ERROR: Please close all manipulators available from "
+                         "the left toolbar first"));
+        return false;
+    }
+    return true;
+}
+
 void GLGizmosManager::set_hover_id(int id)
 {
     if (!m_enabled || m_current == Undefined)
@@ -1194,10 +1206,10 @@ std::string GLGizmosManager::update_hover_state(const Vec2d& mouse_pos)
     return name;
 }
 
-void GLGizmosManager::activate_gizmo(EType type)
+bool GLGizmosManager::activate_gizmo(EType type)
 {
     if (m_gizmos.empty() || m_current == type)
-        return;
+        return true;
 
     GLGizmoBase* old_gizmo = m_current == Undefined ? nullptr : m_gizmos[m_current].get();
     GLGizmoBase* new_gizmo = type == Undefined ? nullptr : m_gizmos[type].get();
@@ -1205,7 +1217,7 @@ void GLGizmosManager::activate_gizmo(EType type)
     if (old_gizmo) {
         old_gizmo->set_state(GLGizmoBase::Off);
         if (old_gizmo->get_state() != GLGizmoBase::Off)
-            return; // gizmo refused to be turned off, do nothing.
+            return false; // gizmo refused to be turned off, do nothing.
 
         if (! m_parent.get_gizmos_manager().is_serializing()
          && old_gizmo->wants_enter_leave_snapshots())
@@ -1222,6 +1234,7 @@ void GLGizmosManager::activate_gizmo(EType type)
 
     if (new_gizmo)
         new_gizmo->set_state(GLGizmoBase::On);
+    return true;
 }
 
 
diff --git a/src/slic3r/GUI/Gizmos/GLGizmosManager.hpp b/src/slic3r/GUI/Gizmos/GLGizmosManager.hpp
index 188c9e914..ed02574df 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmosManager.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmosManager.hpp
@@ -104,7 +104,7 @@ private:
     std::vector<size_t> get_selectable_idxs() const;
     size_t get_gizmo_idx_from_mouse(const Vec2d& mouse_pos) const;
 
-    void activate_gizmo(EType type);
+    bool activate_gizmo(EType type);
 
     struct MouseCapture
     {
@@ -176,6 +176,7 @@ public:
     void reset_all_states();
     bool is_serializing() const { return m_serializing; }
     bool open_gizmo(EType type);
+    bool check_gizmos_closed_except(EType) const;
 
     void set_hover_id(int id);
     void enable_grabber(EType type, unsigned int id, bool enable);
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 4236ee450..af8734184 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -3186,6 +3186,9 @@ void Plater::priv::update_sla_scene()
 
 void Plater::priv::replace_with_stl()
 {
+    if (! q->canvas3D()->get_gizmos_manager().check_gizmos_closed_except(GLGizmosManager::EType::Undefined))
+        return;
+
     const Selection& selection = get_selection();
 
     if (selection.is_wipe_tower() || get_selection().get_volume_idxs().size() != 1)
@@ -3530,14 +3533,8 @@ void Plater::priv::fix_through_netfabb(const int obj_idx, const int vol_idx/* =
 
     // Do not fix anything when a gizmo is open. There might be issues with updates
     // and what is worse, the snapshot time would refer to the internal stack.
-    if (q->canvas3D()->get_gizmos_manager().get_current_type() != GLGizmosManager::Undefined) {
-        notification_manager->push_notification(
-                    NotificationType::CustomSupportsAndSeamRemovedAfterRepair,
-                    NotificationManager::NotificationLevel::RegularNotification,
-                    _u8L("ERROR: Please close all manipulators available from "
-                         "the left toolbar before fixing the mesh."));
+    if (! q->canvas3D()->get_gizmos_manager().check_gizmos_closed_except(GLGizmosManager::Undefined))
         return;
-    }
 
     // size_t snapshot_time = undo_redo_stack().active_snapshot_time();
     Plater::TakeSnapshot snapshot(q, _L("Fix through NetFabb"));