diff --git a/src/libslic3r/SLAPrint.hpp b/src/libslic3r/SLAPrint.hpp
index 88b207d82f..c29c4d1cc8 100644
--- a/src/libslic3r/SLAPrint.hpp
+++ b/src/libslic3r/SLAPrint.hpp
@@ -93,7 +93,7 @@ public:
     // to the z coordinate of the object coordinate system.
     struct SliceRecord {
         using Key = long long;
-        inline static float scale_back(Key h) { return float(scale_(h)); }
+        inline static float scale_back(Key h) { return float(h * SCALING_FACTOR); }
 
         using Idx = size_t;
         static const Idx NONE = Idx(-1); // this will be the max limit of size_t
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index 62e996ba14..42df2f4213 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -7003,7 +7003,7 @@ void GLCanvas3D::_load_shells_sla()
             unsigned int partial_volumes_count = (unsigned int)m_volumes.volumes.size();
 
             // add supports
-            if (obj->is_step_done(slaposSupportTree))
+            if (obj->is_step_done(slaposSupportTree) && obj->has_mesh(slaposSupportTree))
             {
                 const TriangleMesh& mesh = obj->support_mesh();
                 m_volumes.volumes.emplace_back(new GLVolume(GLVolume::SLA_SUPPORT_COLOR));
@@ -7021,7 +7021,7 @@ void GLCanvas3D::_load_shells_sla()
             }
 
             // add pad
-            if (obj->is_step_done(slaposBasePool))
+            if (obj->is_step_done(slaposBasePool) && obj->has_mesh(slaposBasePool))
             {
                 const TriangleMesh& mesh = obj->pad_mesh();
                 m_volumes.volumes.emplace_back(new GLVolume(GLVolume::SLA_PAD_COLOR));
diff --git a/src/slic3r/GUI/GUI_Preview.cpp b/src/slic3r/GUI/GUI_Preview.cpp
index 5b0153c20e..cae7440f68 100644
--- a/src/slic3r/GUI/GUI_Preview.cpp
+++ b/src/slic3r/GUI/GUI_Preview.cpp
@@ -22,6 +22,7 @@
 
 // this include must follow the wxWidgets ones or it won't compile on Windows -> see http://trac.wxwidgets.org/ticket/2421
 #include "libslic3r/Print.hpp"
+#include "libslic3r/SLAPrint.hpp"
 
 namespace Slic3r {
 namespace GUI {
@@ -326,10 +327,10 @@ void Preview::reset_sliders()
     m_double_slider_sizer->Hide((size_t)0);
 }
 
-void Preview::update_sliders()
+void Preview::update_sliders(const std::vector<double>& layers_z)
 {
     m_enabled = true;
-    update_double_slider(m_force_sliders_full_range);
+    update_double_slider(layers_z, m_force_sliders_full_range);
     m_double_slider_sizer->Show((size_t)0);
     Layout();
 }
@@ -402,10 +403,9 @@ void Preview::create_double_slider()
         });
 }
 
-void Preview::update_double_slider(bool force_sliders_full_range)
+void Preview::update_double_slider(const std::vector<double>& layers_z, bool force_sliders_full_range)
 {
     std::vector<std::pair<int, double>> values;
-    std::vector<double> layers_z = m_canvas->get_current_print_zs(true);
     fill_slider_values(values, layers_z);
 
     const double z_low = m_slider->GetLowerValueD();
@@ -606,7 +606,7 @@ void Preview::load_print_as_fff()
         }
 
         if (n_layers > 0)
-            update_sliders();
+            update_sliders(m_canvas->get_current_print_zs(true));
 
         m_loaded = true;
     }
@@ -617,9 +617,44 @@ void Preview::load_print_as_sla()
     if (m_loaded || (m_process->current_printer_technology() != ptSLA))
         return;
 
-    std::cout << "Preview::load_print_as_sla()" << std::endl;
-    m_canvas->load_sla_preview();
-    show_hide_ui_elements("none");
+    unsigned int n_layers = 0;
+    const SLAPrint* print = m_process->sla_print();
+
+    std::set<float> zs;
+    for (const SLAPrintObject* obj : print->objects())
+    {
+        if (obj->is_step_done(slaposIndexSlices))
+        {
+            const SLAPrintObject::SliceIndex& index = obj->get_slice_index();
+            for (const SLAPrintObject::SliceIndex::value_type& id : index)
+            {
+                zs.insert(id.second.scale_back(id.first));
+            }
+        }
+    }
+
+    n_layers = (unsigned int)zs.size();
+    if (n_layers == 0)
+    {
+        reset_sliders();
+        m_canvas_widget->Refresh();
+    }
+
+    if (IsShown())
+    {
+        std::cout << "Preview::load_print_as_sla()" << std::endl;
+        m_canvas->load_sla_preview();
+        show_hide_ui_elements("none");
+
+        if (n_layers > 0)
+        {
+            std::vector<double> layer_zs;
+            std::copy(zs.begin(), zs.end(), std::back_inserter(layer_zs));
+            update_sliders(layer_zs);
+        }
+
+        m_loaded = true;
+    }
 }
 
 } // namespace GUI
diff --git a/src/slic3r/GUI/GUI_Preview.hpp b/src/slic3r/GUI/GUI_Preview.hpp
index 9a175205cb..902ead38d4 100644
--- a/src/slic3r/GUI/GUI_Preview.hpp
+++ b/src/slic3r/GUI/GUI_Preview.hpp
@@ -85,7 +85,7 @@ private:
     void show_hide_ui_elements(const std::string& what);
 
     void reset_sliders();
-    void update_sliders();
+    void update_sliders(const std::vector<double>& layers_z);
 
     void on_size(wxSizeEvent& evt);
     void on_choice_view_type(wxCommandEvent& evt);
@@ -97,8 +97,8 @@ private:
 
     // Create/Update/Reset double slider on 3dPreview
     void create_double_slider();
-    void update_double_slider(bool force_sliders_full_range);
-    void fill_slider_values(std::vector<std::pair<int, double>> &values, 
+    void update_double_slider(const std::vector<double>& layers_z, bool force_sliders_full_range);
+    void fill_slider_values(std::vector<std::pair<int, double>> &values,
                             const std::vector<double> &layers_z);
     void set_double_slider_thumbs(  const bool force_sliders_full_range, 
                                     const std::vector<double> &layers_z,