diff --git a/resources/icons/Slic3r_32px.png b/resources/icons/Slic3r_32px.png
new file mode 100644
index 0000000000..6bf5a9cd14
Binary files /dev/null and b/resources/icons/Slic3r_32px.png differ
diff --git a/resources/icons/overlay/sla_support_points_hover.png b/resources/icons/overlay/sla_support_points_hover.png
index 6303232b24..55955f3d6f 100644
Binary files a/resources/icons/overlay/sla_support_points_hover.png and b/resources/icons/overlay/sla_support_points_hover.png differ
diff --git a/resources/icons/overlay/sla_support_points_off.png b/resources/icons/overlay/sla_support_points_off.png
index b654366d57..7bf84a3e64 100644
Binary files a/resources/icons/overlay/sla_support_points_off.png and b/resources/icons/overlay/sla_support_points_off.png differ
diff --git a/resources/icons/overlay/sla_support_points_on.png b/resources/icons/overlay/sla_support_points_on.png
index 8c1e695650..879b9b2412 100644
Binary files a/resources/icons/overlay/sla_support_points_on.png and b/resources/icons/overlay/sla_support_points_on.png differ
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index 7facc36232..3c4debba04 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -1549,7 +1549,7 @@ void GLCanvas3D::Selection::start_dragging()
     _set_caches();
 }
 
-void GLCanvas3D::Selection::translate(const Vec3d& displacement)
+void GLCanvas3D::Selection::translate(const Vec3d& displacement, bool local)
 {
     if (!m_valid)
         return;
@@ -1559,7 +1559,7 @@ void GLCanvas3D::Selection::translate(const Vec3d& displacement)
 #if ENABLE_MODELVOLUME_TRANSFORM
     if ((m_mode == Volume) || (*m_volumes)[i]->is_wipe_tower)
     {
-        if (_requires_local_axes())
+        if (local)
             (*m_volumes)[i]->set_volume_offset(m_cache.volumes_data[i].get_volume_position() + displacement);
         else
         {
@@ -1614,7 +1614,7 @@ void GLCanvas3D::Selection::rotate(const Vec3d& rotation, bool local)
         else if (is_single_volume() || is_single_modifier())
 #if ENABLE_WORLD_ROTATIONS
         {
-            if (_requires_local_axes())
+            if (requires_local_axes())
                 (*m_volumes)[i]->set_volume_rotation(rotation);
             else
             {
@@ -2118,6 +2118,11 @@ void GLCanvas3D::Selection::render_sidebar_hints(const std::string& sidebar_fiel
 }
 #endif // ENABLE_SIDEBAR_VISUAL_HINTS
 
+bool GLCanvas3D::Selection::requires_local_axes() const
+{
+    return (m_mode == Volume) && is_from_single_instance();
+}
+
 void GLCanvas3D::Selection::_update_valid()
 {
     m_valid = (m_volumes != nullptr) && (m_model != nullptr);
@@ -2746,11 +2751,6 @@ void GLCanvas3D::Selection::_ensure_on_bed()
 }
 #endif // ENABLE_ENSURE_ON_BED_WHILE_SCALING
 
-bool GLCanvas3D::Selection::_requires_local_axes() const
-{
-    return (m_mode == Volume) && is_from_single_instance();
-}
-
 const float GLCanvas3D::Gizmos::OverlayIconsScale = 1.0f;
 const float GLCanvas3D::Gizmos::OverlayBorder = 5.0f;
 const float GLCanvas3D::Gizmos::OverlayGapY = 5.0f * OverlayIconsScale;
diff --git a/src/slic3r/GUI/GLCanvas3D.hpp b/src/slic3r/GUI/GLCanvas3D.hpp
index 54e546c78c..413d625f1d 100644
--- a/src/slic3r/GUI/GLCanvas3D.hpp
+++ b/src/slic3r/GUI/GLCanvas3D.hpp
@@ -578,7 +578,7 @@ public:
 
         void start_dragging();
 
-        void translate(const Vec3d& displacement);
+        void translate(const Vec3d& displacement, bool local = false);
         void rotate(const Vec3d& rotation, bool local);
         void flattening_rotate(const Vec3d& normal);
         void scale(const Vec3d& scale, bool local);
@@ -597,6 +597,8 @@ public:
         void render_sidebar_hints(const std::string& sidebar_field) const;
 #endif // ENABLE_SIDEBAR_VISUAL_HINTS
 
+        bool requires_local_axes() const;
+
     private:
         void _update_valid();
         void _update_type();
@@ -626,7 +628,6 @@ public:
 #if ENABLE_ENSURE_ON_BED_WHILE_SCALING
         void _ensure_on_bed();
 #endif // ENABLE_ENSURE_ON_BED_WHILE_SCALING
-        bool _requires_local_axes() const;
     };
 
     class ClippingPlane
diff --git a/src/slic3r/GUI/GUI_App.cpp b/src/slic3r/GUI/GUI_App.cpp
index 88c77c1937..bbba1d93ba 100644
--- a/src/slic3r/GUI/GUI_App.cpp
+++ b/src/slic3r/GUI/GUI_App.cpp
@@ -137,7 +137,7 @@ bool GUI_App::OnInit()
     std::cerr << "Creating main frame..." << std::endl;
     if (wxImage::FindHandler(wxBITMAP_TYPE_PNG) == nullptr)
         wxImage::AddHandler(new wxPNGHandler());
-    mainframe = new MainFrame(no_plater, false);
+    mainframe = new MainFrame();
     sidebar().obj_list()->init_objects(); // propagate model objects to object list
     update_mode();
     SetTopWindow(mainframe);
@@ -277,8 +277,8 @@ void GUI_App::recreate_GUI()
 {
     std::cerr << "recreate_GUI" << std::endl;
 
-    auto topwindow = GetTopWindow();
-    mainframe = new MainFrame(no_plater,false);
+    MainFrame* topwindow = dynamic_cast<MainFrame*>(GetTopWindow());
+    mainframe = new MainFrame();
     sidebar().obj_list()->init_objects(); // propagate model objects to object list
     update_mode();
 
@@ -287,6 +287,20 @@ void GUI_App::recreate_GUI()
         topwindow->Destroy();
     }
 
+    m_printhost_job_queue.reset(new PrintHostJobQueue(mainframe->printhost_queue_dlg()));
+
+    CallAfter([this]() {
+        // temporary workaround for the correct behavior of the Scrolled sidebar panel
+        auto& panel = sidebar();
+        if (panel.obj_list()->GetMinHeight() > 200) {
+            wxWindowUpdateLocker noUpdates_sidebar(&panel);
+            panel.obj_list()->SetMinSize(wxSize(-1, 200));
+            panel.Layout();
+        }
+    });
+ 
+    mainframe->Show(true);
+
     // On OSX the UI was not initialized correctly if the wizard was called
     // before the UI was up and running.
     CallAfter([]() {
@@ -434,7 +448,7 @@ bool GUI_App::select_language(  wxArrayString & names,
         m_wxLocale = new wxLocale;
         m_wxLocale->Init(identifiers[index]);
         m_wxLocale->AddCatalogLookupPathPrefix(localization_dir());
-        m_wxLocale->AddCatalog(GetAppName());
+        m_wxLocale->AddCatalog(/*GetAppName()*/"Slic3rPE");
         wxSetlocale(LC_NUMERIC, "C");
         Preset::update_suffix_modified();
         return true;
@@ -461,7 +475,7 @@ bool GUI_App::load_language()
             m_wxLocale = new wxLocale;
             m_wxLocale->Init(identifiers[i]);
             m_wxLocale->AddCatalogLookupPathPrefix(localization_dir());
-            m_wxLocale->AddCatalog(GetAppName());
+            m_wxLocale->AddCatalog(/*GetAppName()*/"Slic3rPE");
             wxSetlocale(LC_NUMERIC, "C");
             Preset::update_suffix_modified();
             return true;
@@ -504,7 +518,8 @@ void GUI_App::get_installed_languages(wxArrayString & names, wxArrayLong & ident
         {
             auto full_file_name = dir.GetName() + wxFileName::GetPathSeparator() +
                 filename + wxFileName::GetPathSeparator() +
-                GetAppName() + wxT(".mo");
+                /*GetAppName()*/"Slic3rPE" + 
+                wxT(".mo");
             if (wxFileExists(full_file_name))
             {
                 names.Add(langinfo->Description);
diff --git a/src/slic3r/GUI/GUI_App.hpp b/src/slic3r/GUI/GUI_App.hpp
index 81175b7cac..bd64a3ac57 100644
--- a/src/slic3r/GUI/GUI_App.hpp
+++ b/src/slic3r/GUI/GUI_App.hpp
@@ -71,7 +71,6 @@ static wxString dots("…", wxConvUTF8);
 
 class GUI_App : public wxApp
 {
-    bool            no_plater{ false };
     bool            app_conf_exists{ false };
 
     // Lock to guard the callback stack
diff --git a/src/slic3r/GUI/GUI_ObjectManipulation.cpp b/src/slic3r/GUI/GUI_ObjectManipulation.cpp
index ddf699c2cd..8cc2362e82 100644
--- a/src/slic3r/GUI/GUI_ObjectManipulation.cpp
+++ b/src/slic3r/GUI/GUI_ObjectManipulation.cpp
@@ -361,8 +361,9 @@ void ObjectManipulation::update_rotation_value(const Vec3d& rotation)
 void ObjectManipulation::change_position_value(const Vec3d& position)
 {
     auto canvas = wxGetApp().plater()->canvas3D();
-    canvas->get_selection().start_dragging();
-    canvas->get_selection().translate(position - cache_position);
+    GLCanvas3D::Selection& selection = canvas->get_selection();
+    selection.start_dragging();
+    selection.translate(position - cache_position, selection.requires_local_axes());
     canvas->do_move();
 
     cache_position = position;
diff --git a/src/slic3r/GUI/GUI_Preview.cpp b/src/slic3r/GUI/GUI_Preview.cpp
index 579cd7e5ec..988a7b6a13 100644
--- a/src/slic3r/GUI/GUI_Preview.cpp
+++ b/src/slic3r/GUI/GUI_Preview.cpp
@@ -586,7 +586,8 @@ void Preview::create_double_slider()
             auto& config = wxGetApp().preset_bundle->project_config;
             ((config.option<ConfigOptionFloats>("colorprint_heights"))->values) = (m_slider->GetTicksValues());
             m_schedule_background_process();
-            int type = m_choice_view_type->FindString(_(L("Color Print")));
+            bool color_print = !config.option<ConfigOptionFloats>("colorprint_heights")->values.empty();
+            int type = m_choice_view_type->FindString(color_print ? _(L("Color Print")) : _(L("Feature type")) );
             if (m_choice_view_type->GetSelection() != type) {
                 m_choice_view_type->SetSelection(type);
                 if ((0 <= type) && (type < (int)GCodePreviewData::Extrusion::Num_View_Types))
diff --git a/src/slic3r/GUI/KBShortcutsDialog.cpp b/src/slic3r/GUI/KBShortcutsDialog.cpp
index 87010f0817..b3edbc9a8b 100644
--- a/src/slic3r/GUI/KBShortcutsDialog.cpp
+++ b/src/slic3r/GUI/KBShortcutsDialog.cpp
@@ -23,7 +23,7 @@ KBShortcutsDialog::KBShortcutsDialog()
 
     wxFont font = wxSystemSettings::GetFont(wxSYS_DEFAULT_GUI_FONT);
     font.SetPointSize(10);
-    const wxFont bold_font = font.Bold();
+    wxFont bold_font = font.Bold();
 #ifdef __WXOSX__
     font.SetPointSize(12);
     bold_font.SetPointSize(14);
diff --git a/src/slic3r/GUI/MainFrame.cpp b/src/slic3r/GUI/MainFrame.cpp
index 2211023f06..871d50a3d0 100644
--- a/src/slic3r/GUI/MainFrame.cpp
+++ b/src/slic3r/GUI/MainFrame.cpp
@@ -28,10 +28,8 @@
 namespace Slic3r {
 namespace GUI {
 
-MainFrame::MainFrame(const bool no_plater, const bool loaded) :
+MainFrame::MainFrame() :
 wxFrame(NULL, wxID_ANY, SLIC3R_BUILD, wxDefaultPosition, wxDefaultSize, wxDEFAULT_FRAME_STYLE),
-        m_no_plater(no_plater),
-        m_loaded(loaded),
         m_printhost_queue_dlg(new PrintHostQueueDialog(this))
 {
     // Load the icon either from the exe, or from the ico file.
@@ -125,11 +123,9 @@ void MainFrame::init_tabpanel()
         }
     });
 
-    if (!m_no_plater) {
-        m_plater = new Slic3r::GUI::Plater(m_tabpanel, this);
-        wxGetApp().plater_ = m_plater;
-        m_tabpanel->AddPage(m_plater, _(L("Plater")));
-    }
+    m_plater = new Slic3r::GUI::Plater(m_tabpanel, this);
+    wxGetApp().plater_ = m_plater;
+    m_tabpanel->AddPage(m_plater, _(L("Plater")));
 
     // The following event is emited by Tab implementation on config value change.
     Bind(EVT_TAB_VALUE_CHANGED, &MainFrame::on_value_changed, this);
diff --git a/src/slic3r/GUI/MainFrame.hpp b/src/slic3r/GUI/MainFrame.hpp
index fab6aea908..e0411b6dad 100644
--- a/src/slic3r/GUI/MainFrame.hpp
+++ b/src/slic3r/GUI/MainFrame.hpp
@@ -42,10 +42,7 @@ struct PresetTab {
 
 class MainFrame : public wxFrame
 {
-    bool        m_no_plater;
-    bool        m_loaded;
-    int         m_lang_ch_event;
-    int         m_preferences_event;
+    bool        m_loaded {false};
 
     wxString    m_qs_last_input_file = wxEmptyString;
     wxString    m_qs_last_output_file = wxEmptyString;
@@ -71,8 +68,7 @@ class MainFrame : public wxFrame
     bool can_delete_all() const;
 
 public:
-    MainFrame() {}
-    MainFrame(const bool no_plater, const bool loaded);
+    MainFrame();
     ~MainFrame() {}
 
     Plater*     plater() { return m_plater; }
diff --git a/src/slic3r/GUI/PrintHostDialogs.cpp b/src/slic3r/GUI/PrintHostDialogs.cpp
index 8ac8615a84..586fe3d835 100644
--- a/src/slic3r/GUI/PrintHostDialogs.cpp
+++ b/src/slic3r/GUI/PrintHostDialogs.cpp
@@ -102,7 +102,7 @@ PrintHostQueueDialog::PrintHostQueueDialog(wxWindow *parent)
     job_list->AppendTextColumn("Filename", wxDATAVIEW_CELL_INERT);
 
     auto *btnsizer = new wxBoxSizer(wxHORIZONTAL);
-    auto *btn_cancel = new wxButton(this, wxID_DELETE, _(L("Cancel selected")));
+    auto *btn_cancel = new wxButton(this, wxID_DELETE, _(L("Cancel selected")));   // TODO: enable based on status ("show error" for failed jobs)
     auto *btn_close = new wxButton(this, wxID_CANCEL, _(L("Close")));
     btnsizer->Add(btn_cancel, 0, wxRIGHT, SPACING);
     btnsizer->AddStretchSpacer();
@@ -140,7 +140,13 @@ void PrintHostQueueDialog::on_error(Event &evt)
 {
     wxCHECK_RET(evt.job_id < job_list->GetItemCount(), "Out of bounds access to job list");
 
-    // TODO
+    job_list->SetValue(wxVariant(0), evt.job_id, 1);
+    job_list->SetValue(wxVariant(_(L("Error"))), evt.job_id, 2);
+
+    // TODO: keep the error for repeated display
+
+    auto errormsg = wxString::Format("%s\n%s", _(L("Error uploading to print host:")), evt.error);
+    GUI::show_error(nullptr, std::move(errormsg));
 }
 
 
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index 0b59a21aba..5a212d4ee2 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -1551,7 +1551,7 @@ void TabPrinter::build_printhost(ConfigOptionsGroup *optgroup)
 
 	auto printhost_browse = [this, optgroup] (wxWindow* parent) {
 
-		// TODO: SLA
+		// TODO: SLA Bonjour
 
 		auto btn = m_printhost_browse_btn = new wxButton(parent, wxID_ANY, _(L(" Browse "))+dots, wxDefaultPosition, wxDefaultSize, wxBU_LEFT);
 		btn->SetBitmap(wxBitmap(from_u8(Slic3r::var("zoom.png")), wxBITMAP_TYPE_PNG));
@@ -1562,6 +1562,7 @@ void TabPrinter::build_printhost(ConfigOptionsGroup *optgroup)
 			BonjourDialog dialog(parent);
 			if (dialog.show_and_lookup()) {
 				optgroup->set_value("print_host", std::move(dialog.get_selected()), true);
+				// FIXME: emit killfocus on the edit widget
 			}
 		});
 
diff --git a/src/slic3r/GUI/wxExtensions.cpp b/src/slic3r/GUI/wxExtensions.cpp
index 787c2a2a2a..dc917f8755 100644
--- a/src/slic3r/GUI/wxExtensions.cpp
+++ b/src/slic3r/GUI/wxExtensions.cpp
@@ -2058,7 +2058,7 @@ void PrusaDoubleSlider::enter_window(wxMouseEvent& event, const bool enter)
 //    -  value decrease (if wxSL_HORIZONTAL) 
 void PrusaDoubleSlider::move_current_thumb(const bool condition)
 {
-    m_is_one_layer = wxGetKeyState(WXK_CONTROL);
+//     m_is_one_layer = wxGetKeyState(WXK_CONTROL);
     int delta = condition ? -1 : 1;
     if (is_horizontal())
         delta *= -1;
diff --git a/src/slic3r/Utils/Duet.cpp b/src/slic3r/Utils/Duet.cpp
index 1772ae8ef4..fd77fc1300 100644
--- a/src/slic3r/Utils/Duet.cpp
+++ b/src/slic3r/Utils/Duet.cpp
@@ -46,7 +46,7 @@ bool Duet::test(wxString &msg) const
 
 wxString Duet::get_test_ok_msg () const
 {
-	return wxString::Format("%s", _(L("Connection to Duet works correctly.")));
+	return _(L("Connection to Duet works correctly."));
 }
 
 wxString Duet::get_test_failed_msg (wxString &msg) const
@@ -135,7 +135,7 @@ wxString Duet::get_test_failed_msg (wxString &msg) const
 // 	return res;
 // }
 
-bool Duet::upload(PrintHostUpload upload_data, Http::ProgressFn prorgess_fn, Http::ErrorFn error_fn) const
+bool Duet::upload(PrintHostUpload upload_data, ProgressFn prorgess_fn, ErrorFn error_fn) const
 {
 	// XXX: TODO
 	throw "unimplemented";
diff --git a/src/slic3r/Utils/Duet.hpp b/src/slic3r/Utils/Duet.hpp
index 0608f85a58..e053f91eff 100644
--- a/src/slic3r/Utils/Duet.hpp
+++ b/src/slic3r/Utils/Duet.hpp
@@ -19,12 +19,12 @@ public:
 	Duet(DynamicPrintConfig *config);
 	virtual ~Duet();
 
-	bool test(wxString &curl_msg) const;
-	wxString get_test_ok_msg () const;
-	wxString get_test_failed_msg (wxString &msg) const;
-	bool upload(PrintHostUpload upload_data, Http::ProgressFn prorgess_fn, Http::ErrorFn error_fn) const;
-	bool has_auto_discovery() const;
-	bool can_test() const;
+	virtual bool test(wxString &curl_msg) const;
+	virtual wxString get_test_ok_msg () const;
+	virtual wxString get_test_failed_msg (wxString &msg) const;
+	virtual bool upload(PrintHostUpload upload_data, ProgressFn prorgess_fn, ErrorFn error_fn) const;
+	virtual bool has_auto_discovery() const;
+	virtual bool can_test() const;
 	virtual std::string get_host() const { return host; }
 private:
 	std::string host;
diff --git a/src/slic3r/Utils/Http.cpp b/src/slic3r/Utils/Http.cpp
index 6e6c9ed44b..30478cb01b 100644
--- a/src/slic3r/Utils/Http.cpp
+++ b/src/slic3r/Utils/Http.cpp
@@ -32,6 +32,7 @@ class CurlGlobalInit
 struct Http::priv
 {
 	enum {
+		DEFAULT_TIMEOUT = 10,
 		DEFAULT_SIZE_LIMIT = 5 * 1024 * 1024,
 	};
 
@@ -63,6 +64,7 @@ struct Http::priv
 	static int xfercb_legacy(void *userp, double dltotal, double dlnow, double ultotal, double ulnow);
 	static size_t form_file_read_cb(char *buffer, size_t size, size_t nitems, void *userp);
 
+	void set_timeout(long timeout);
 	void form_add_file(const char *name, const fs::path &path, const char* filename);
 	void set_post_body(const fs::path &path);
 
@@ -84,6 +86,7 @@ Http::priv::priv(const std::string &url)
 		throw std::runtime_error(std::string("Could not construct Curl object"));
 	}
 
+	set_timeout(DEFAULT_TIMEOUT);
 	::curl_easy_setopt(curl, CURLOPT_URL, url.c_str());   // curl makes a copy internally
 	::curl_easy_setopt(curl, CURLOPT_USERAGENT, SLIC3R_FORK_NAME "/" SLIC3R_VERSION);
 	::curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, &error_buffer.front());
@@ -167,6 +170,12 @@ size_t Http::priv::form_file_read_cb(char *buffer, size_t size, size_t nitems, v
 	return stream->gcount();
 }
 
+void Http::priv::set_timeout(long timeout)
+{
+	::curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, timeout);
+	::curl_easy_setopt(curl, CURLOPT_TIMEOUT, timeout);
+}
+
 void Http::priv::form_add_file(const char *name, const fs::path &path, const char* filename)
 {
 	// We can't use CURLFORM_FILECONTENT, because curl doesn't support Unicode filenames on Windows
@@ -203,10 +212,10 @@ void Http::priv::set_post_body(const fs::path &path)
 
 std::string Http::priv::curl_error(CURLcode curlcode)
 {
-	return (boost::format("%1% (%2%): %3%")
+	return (boost::format("%1%:\n%2%\n[Error %3%]")
 		% ::curl_easy_strerror(curlcode)
+		% error_buffer.c_str()
 		% curlcode
-		% error_buffer
 	).str();
 }
 
@@ -293,6 +302,13 @@ Http::~Http()
 }
 
 
+Http& Http::timeout(long timeout)
+{
+	if (timeout < 1) { timeout = priv::DEFAULT_TIMEOUT; }
+	if (p) { p->set_timeout(timeout); }
+	return *this;
+}
+
 Http& Http::size_limit(size_t sizeLimit)
 {
 	if (p) { p->limit = sizeLimit; }
diff --git a/src/slic3r/Utils/Http.hpp b/src/slic3r/Utils/Http.hpp
index fd3f8830dd..9406a82f2e 100644
--- a/src/slic3r/Utils/Http.hpp
+++ b/src/slic3r/Utils/Http.hpp
@@ -55,6 +55,8 @@ public:
 	Http& operator=(const Http &) = delete;
 	Http& operator=(Http &&) = delete;
 
+	// Sets a maximum connection timeout in seconds
+	Http& timeout(long timeout);
 	// Sets a maximum size of the data that can be received.
 	// A value of zero sets the default limit, which is is 5MB.
 	Http& size_limit(size_t sizeLimit);
diff --git a/src/slic3r/Utils/OctoPrint.cpp b/src/slic3r/Utils/OctoPrint.cpp
index cbb81c54f8..af9d6e4f0e 100644
--- a/src/slic3r/Utils/OctoPrint.cpp
+++ b/src/slic3r/Utils/OctoPrint.cpp
@@ -1,8 +1,12 @@
 #include "OctoPrint.hpp"
 
 #include <algorithm>
+#include <sstream>
 #include <boost/format.hpp>
 #include <boost/log/trivial.hpp>
+#include <boost/property_tree/ptree.hpp>
+#include <boost/property_tree/json_parser.hpp>
+#include <boost/algorithm/string/predicate.hpp>
 
 #include <wx/progdlg.h>
 
@@ -12,6 +16,7 @@
 
 
 namespace fs = boost::filesystem;
+namespace pt = boost::property_tree;
 
 
 namespace Slic3r {
@@ -41,11 +46,29 @@ bool OctoPrint::test(wxString &msg) const
             res = false;
             msg = format_error(body, error, status);
         })
-        .on_complete([&](std::string body, unsigned) {
+        .on_complete([&, this](std::string body, unsigned) {
             BOOST_LOG_TRIVIAL(debug) << boost::format("Octoprint: Got version: %1%") % body;
 
-            // TODO: parse body, call validate_version_text
+            try {
+                std::stringstream ss(body);
+                pt::ptree ptree;
+                pt::read_json(ss, ptree);
 
+                if (! ptree.get_optional<std::string>("api")) {
+                    res = false;
+                    return;
+                }
+
+                const auto text = ptree.get_optional<std::string>("text");
+                res = validate_version_text(text);
+                if (! res) {
+                    msg = wxString::Format(_(L("Mismatched type of print host: %s")), text ? *text : "OctoPrint");
+                }
+            }
+            catch (...) {
+                res = false;
+                msg = "Could not parse server response";
+            }
         })
         .perform_sync();
 
@@ -54,28 +77,24 @@ bool OctoPrint::test(wxString &msg) const
 
 wxString OctoPrint::get_test_ok_msg () const
 {
-    return wxString::Format("%s", _(L("Connection to OctoPrint works correctly.")));
+    return _(L("Connection to OctoPrint works correctly."));
 }
 
 wxString OctoPrint::get_test_failed_msg (wxString &msg) const
 {
     return wxString::Format("%s: %s\n\n%s",
-                        _(L("Could not connect to OctoPrint")), msg, _(L("Note: OctoPrint version at least 1.1.0 is required.")));
+        _(L("Could not connect to OctoPrint")), msg, _(L("Note: OctoPrint version at least 1.1.0 is required.")));
 }
 
-bool OctoPrint::upload(PrintHostUpload upload_data, Http::ProgressFn prorgess_fn, Http::ErrorFn error_fn) const
+bool OctoPrint::upload(PrintHostUpload upload_data, ProgressFn prorgess_fn, ErrorFn error_fn) const
 {
     const auto upload_filename = upload_data.upload_path.filename();
     const auto upload_parent_path = upload_data.upload_path.parent_path();
 
     wxString test_msg;
     if (! test(test_msg)) {
-
-        // TODO:
-
-        // auto errormsg = wxString::Format("%s: %s", errortitle, test_msg);
-        // GUI::show_error(&progress_dialog, std::move(errormsg));
-        // return false;
+        error_fn(std::move(test_msg));
+        return false;
     }
 
     bool res = true;
@@ -99,7 +118,8 @@ bool OctoPrint::upload(PrintHostUpload upload_data, Http::ProgressFn prorgess_fn
         })
         .on_error([&](std::string body, std::string error, unsigned status) {
             BOOST_LOG_TRIVIAL(error) << boost::format("Octoprint: Error uploading file: %1%, HTTP %2%, body: `%3%`") % error % status % body;
-            error_fn(std::move(body), std::move(error), status);
+            // error_fn(std::move(body), std::move(error), status);
+            error_fn(format_error(body, error, status));
             res = false;
         })
         .on_progress([&](Http::Progress progress, bool &cancel) {
@@ -125,10 +145,9 @@ bool OctoPrint::can_test() const
     return true;
 }
 
-bool OctoPrint::validate_version_text(const std::string &version_text)
+bool OctoPrint::validate_version_text(const boost::optional<std::string> &version_text) const
 {
-    // FIXME
-    return true;
+    return version_text ? boost::starts_with(*version_text, "OctoPrint") : true;
 }
 
 void OctoPrint::set_auth(Http &http) const
@@ -164,14 +183,23 @@ wxString OctoPrint::format_error(const std::string &body, const std::string &err
 }
 
 
-// SL1
+// SLAHost
 
-SL1Host::~SL1Host() {}
+SLAHost::~SLAHost() {}
 
-bool SL1Host::validate_version_text(const std::string &version_text)
+wxString SLAHost::get_test_ok_msg () const
 {
-    // FIXME
-    return true;
+    return _(L("Connection to Prusa SLA works correctly."));
+}
+
+wxString SLAHost::get_test_failed_msg (wxString &msg) const
+{
+    return wxString::Format("%s: %s", _(L("Could not connect to Prusa SLA")), msg);
+}
+
+bool SLAHost::validate_version_text(const boost::optional<std::string> &version_text) const
+{
+    return version_text ? boost::starts_with(*version_text, "Prusa SLA") : false;
 }
 
 
diff --git a/src/slic3r/Utils/OctoPrint.hpp b/src/slic3r/Utils/OctoPrint.hpp
index 4d6555e13f..1e739c99d7 100644
--- a/src/slic3r/Utils/OctoPrint.hpp
+++ b/src/slic3r/Utils/OctoPrint.hpp
@@ -3,6 +3,7 @@
 
 #include <string>
 #include <wx/string.h>
+#include <boost/optional.hpp>
 
 #include "PrintHost.hpp"
 
@@ -19,16 +20,16 @@ public:
     OctoPrint(DynamicPrintConfig *config);
     virtual ~OctoPrint();
 
-    bool test(wxString &curl_msg) const;
-    wxString get_test_ok_msg () const;
-    wxString get_test_failed_msg (wxString &msg) const;
-    bool upload(PrintHostUpload upload_data, Http::ProgressFn prorgess_fn, Http::ErrorFn error_fn) const;
-    bool has_auto_discovery() const;
-    bool can_test() const;
+    virtual bool test(wxString &curl_msg) const;
+    virtual wxString get_test_ok_msg () const;
+    virtual wxString get_test_failed_msg (wxString &msg) const;
+    virtual bool upload(PrintHostUpload upload_data, ProgressFn prorgess_fn, ErrorFn error_fn) const;
+    virtual bool has_auto_discovery() const;
+    virtual bool can_test() const;
     virtual std::string get_host() const { return host; }
 
 protected:
-    virtual bool validate_version_text(const std::string &version_text);
+    virtual bool validate_version_text(const boost::optional<std::string> &version_text) const;
 
 private:
     std::string host;
@@ -41,14 +42,16 @@ private:
 };
 
 
-class SL1Host: public OctoPrint
+class SLAHost: public OctoPrint
 {
 public:
-    SL1Host(DynamicPrintConfig *config) : OctoPrint(config) {}
-    virtual ~SL1Host();
+    SLAHost(DynamicPrintConfig *config) : OctoPrint(config) {}
+    virtual ~SLAHost();
 
+    virtual wxString get_test_ok_msg () const;
+    virtual wxString get_test_failed_msg (wxString &msg) const;
 protected:
-    virtual bool validate_version_text(const std::string &version_text);
+    virtual bool validate_version_text(const boost::optional<std::string> &version_text) const;
 };
 
 
diff --git a/src/slic3r/Utils/PrintHost.cpp b/src/slic3r/Utils/PrintHost.cpp
index cdd0c107ef..934436a190 100644
--- a/src/slic3r/Utils/PrintHost.cpp
+++ b/src/slic3r/Utils/PrintHost.cpp
@@ -2,10 +2,12 @@
 
 #include <vector>
 #include <thread>
+#include <exception>
 #include <boost/optional.hpp>
 #include <boost/log/trivial.hpp>
 #include <boost/filesystem.hpp>
 
+#include <wx/string.h>
 #include <wx/app.h>
 
 #include "libslic3r/PrintConfig.hpp"
@@ -30,8 +32,8 @@ PrintHost* PrintHost::get_print_host(DynamicPrintConfig *config)
 
     switch (opt->value) {
         case htOctoPrint: return new OctoPrint(config);
-        case htSL1:       return new SL1Host(config);
         case htDuet:      return new Duet(config);
+        case htSL1:       return new SLAHost(config);
         default: return nullptr;
     }
 }
@@ -58,7 +60,6 @@ struct PrintHostJobQueue::priv
     void start_bg_thread();
     void bg_thread_main();
     void progress_fn(Http::Progress progress, bool &cancel);
-    void error_fn(std::string body, std::string error, unsigned http_status);
     void perform_job(PrintHostJob the_job);
 };
 
@@ -100,6 +101,9 @@ void PrintHostJobQueue::priv::bg_thread_main()
             }
             job_id++;
         }
+    } catch (const std::exception &e) {
+        auto evt = new PrintHostQueueDialog::Event(GUI::EVT_PRINTHOST_ERROR, queue_dialog->GetId(), job_id, e.what());
+        wxQueueEvent(queue_dialog, evt);
     } catch (...) {
         wxTheApp->OnUnhandledException();
     }
@@ -136,28 +140,28 @@ void PrintHostJobQueue::priv::progress_fn(Http::Progress progress, bool &cancel)
     }
 }
 
-void PrintHostJobQueue::priv::error_fn(std::string body, std::string error, unsigned http_status)
-{
-    // TODO
-}
-
 void PrintHostJobQueue::priv::perform_job(PrintHostJob the_job)
 {
     if (bg_exit || the_job.empty()) { return; }
 
-    BOOST_LOG_TRIVIAL(debug) << boost::format("PrintHostJobQueue/bg_thread: Got job: `%1%` -> `%1%`")
+    BOOST_LOG_TRIVIAL(debug) << boost::format("PrintHostJobQueue/bg_thread: Got job: `%1%` -> `%2%`")
         % the_job.upload_data.upload_path
         % the_job.printhost->get_host();
 
     const fs::path gcode_path = the_job.upload_data.source_path;
 
-    the_job.printhost->upload(std::move(the_job.upload_data),
+    bool success = the_job.printhost->upload(std::move(the_job.upload_data),
         [this](Http::Progress progress, bool &cancel) { this->progress_fn(std::move(progress), cancel); },
-        [this](std::string body, std::string error, unsigned http_status) { this->error_fn(std::move(body), std::move(error), http_status); }
+        [this](wxString error) {
+            auto evt = new PrintHostQueueDialog::Event(GUI::EVT_PRINTHOST_ERROR, queue_dialog->GetId(), job_id, std::move(error));
+            wxQueueEvent(queue_dialog, evt);
+        }
     );
 
-    auto evt = new PrintHostQueueDialog::Event(GUI::EVT_PRINTHOST_PROGRESS, queue_dialog->GetId(), job_id, 100);
-    wxQueueEvent(queue_dialog, evt);
+    if (success) {
+        auto evt = new PrintHostQueueDialog::Event(GUI::EVT_PRINTHOST_PROGRESS, queue_dialog->GetId(), job_id, 100);
+        wxQueueEvent(queue_dialog, evt);
+    }
 
     boost::system::error_code ec;
     fs::remove(gcode_path, ec);
diff --git a/src/slic3r/Utils/PrintHost.hpp b/src/slic3r/Utils/PrintHost.hpp
index 52ef380589..a6c7a47238 100644
--- a/src/slic3r/Utils/PrintHost.hpp
+++ b/src/slic3r/Utils/PrintHost.hpp
@@ -3,6 +3,7 @@
 
 #include <memory>
 #include <string>
+#include <functional>
 #include <boost/filesystem/path.hpp>
 
 #include <wx/string.h>
@@ -28,10 +29,13 @@ class PrintHost
 public:
     virtual ~PrintHost();
 
+    typedef Http::ProgressFn ProgressFn;
+    typedef std::function<void(wxString /* error */)> ErrorFn;
+
     virtual bool test(wxString &curl_msg) const = 0;
     virtual wxString get_test_ok_msg () const = 0;
     virtual wxString get_test_failed_msg (wxString &msg) const = 0;
-    virtual bool upload(PrintHostUpload upload_data, Http::ProgressFn prorgess_fn, Http::ErrorFn error_fn) const = 0;
+    virtual bool upload(PrintHostUpload upload_data, ProgressFn prorgess_fn, ErrorFn error_fn) const = 0;
     virtual bool has_auto_discovery() const = 0;
     virtual bool can_test() const = 0;
     virtual std::string get_host() const = 0;