diff --git a/src/CloneSource.cpp b/src/CloneSource.cpp
index 22d5de6..49b235f 100644
--- a/src/CloneSource.cpp
+++ b/src/CloneSource.cpp
@@ -61,6 +61,12 @@ CloneSource::~CloneSource()
     delete filter_;
 }
 
+void CloneSource::detach()
+{
+    Log::Info("Source '%s' detached from '%s'.", name().c_str(), origin_->name().c_str() );
+    origin_ = nullptr;
+}
+
 void CloneSource::init()
 {
     if (origin_ && origin_->ready_ && origin_->mode_ > Source::UNINITIALIZED && origin_->renderbuffer_) {
@@ -225,6 +231,11 @@ uint CloneSource::texture() const
     return Resource::getTextureBlack();
 }
 
+Source::Failure CloneSource::failed() const
+{
+    return (origin_ == nullptr || origin_->failed()) ? FAIL_FATAL : FAIL_NONE;
+}
+
 void CloneSource::accept(Visitor& v)
 {
     Source::accept(v);
diff --git a/src/CloneSource.h b/src/CloneSource.h
index 6585cd2..5fab548 100644
--- a/src/CloneSource.h
+++ b/src/CloneSource.h
@@ -22,14 +22,14 @@ public:
     void replay () override;
     guint64 playtime () const override;
     uint texture() const override;
-    bool failed() const override  { return origin_ == nullptr || origin_->failed(); }
+    Failure failed() const override;
     void accept (Visitor& v) override;
     void render() override;
     glm::ivec2 icon() const override;
     std::string info() const override;
 
     // implementation of cloning mechanism
-    inline void detach() { origin_ = nullptr; }
+    void detach();
     inline Source *origin() const { return origin_; }
 
     // Filtering
diff --git a/src/DeviceSource.cpp b/src/DeviceSource.cpp
index f460b56..85b063f 100644
--- a/src/DeviceSource.cpp
+++ b/src/DeviceSource.cpp
@@ -26,15 +26,10 @@
 #include <gst/gst.h>
 
 
-#include "defines.h"
 #include "Log.h"
-#include "ImageShader.h"
-#include "ImageProcessingShader.h"
-#include "Resource.h"
 #include "Decorations.h"
 #include "Stream.h"
 #include "Visitor.h"
-#include "CloneSource.h"
 
 #include "DeviceSource.h"
 
@@ -525,9 +520,9 @@ void DeviceSource::accept(Visitor& v)
     v.visit(*this);
 }
 
-bool DeviceSource::failed() const
+Source::Failure DeviceSource::failed() const
 {
-    return unplugged_ || StreamSource::failed();
+    return (unplugged_ || StreamSource::failed()) ? FAIL_CRITICAL : FAIL_NONE;
 }
 
 DeviceConfigSet Device::getDeviceConfigs(const std::string &src_description)
diff --git a/src/DeviceSource.h b/src/DeviceSource.h
index 59181e8..ff70148 100644
--- a/src/DeviceSource.h
+++ b/src/DeviceSource.h
@@ -15,7 +15,7 @@ public:
     ~DeviceSource();
 
     // Source interface
-    bool failed() const override;
+    Failure failed() const override;
     void accept (Visitor& v) override;
     void setActive (bool on) override;
 
diff --git a/src/ImGuiVisitor.cpp b/src/ImGuiVisitor.cpp
index 5d0576b..793afa5 100644
--- a/src/ImGuiVisitor.cpp
+++ b/src/ImGuiVisitor.cpp
@@ -443,9 +443,9 @@ void ImGuiVisitor::visit (Source& s)
         ImGui::SetCursorPos( ImVec2(preview_width + 20, pos.y ) );
         if (s.active()) {
             if (s.blendingShader()->color.a > 0.f)
-                ImGuiToolkit::Indication("Visible", ICON_FA_EYE);
+                ImGuiToolkit::Indication("Visible", ICON_FA_SUN);
             else
-                ImGuiToolkit::Indication("Not visible", ICON_FA_EYE_SLASH);
+                ImGuiToolkit::Indication("Not visible", ICON_FA_CLOUD_SUN);
         }
         else
             ImGuiToolkit::Indication("Inactive", ICON_FA_SNOWFLAKE);
@@ -1142,8 +1142,9 @@ void ImGuiVisitor::visit (CloneSource& s)
     ImGui::Text("%s", info.str().c_str());
     ImGui::PopTextWrapPos();
 
-    // link to origin source
     if ( !s.failed() ) {
+
+        // link to origin source
         std::string label = std::string(s.origin()->initials()) + " - " + s.origin()->name();
         if (ImGui::Button(label.c_str(), ImVec2(IMGUI_RIGHT_ALIGN, 0) )) {
             Mixer::manager().setCurrentSource(s.origin());
@@ -1153,49 +1154,46 @@ void ImGuiVisitor::visit (CloneSource& s)
         }
         ImGui::SameLine(0, IMGUI_SAME_LINE);
         ImGui::Text("Origin");
-    }
-    else {
-        ImGuiToolkit::ButtonDisabled("No source", ImVec2(IMGUI_RIGHT_ALIGN, 0) );
+
+        // filter selection
+        std::ostringstream oss;
+        oss << s.name();
+        int type = (int) s.filter()->type();
+        ImGui::SetNextItemWidth(IMGUI_RIGHT_ALIGN);
+        if (ImGuiToolkit::ComboIcon("##SelectFilter", &type, FrameBufferFilter::Types)) {
+            s.setFilter( FrameBufferFilter::Type(type) );
+            oss << ": Filter " << std::get<2>(FrameBufferFilter::Types[type]);
+            Action::manager().store(oss.str());
+            info.reset();
+        }
         ImGui::SameLine(0, IMGUI_SAME_LINE);
-        ImGui::Text("Origin");
-    }
+        if (ImGuiToolkit::TextButton("Filter")) {
+            s.setFilter( FrameBufferFilter::FILTER_PASSTHROUGH );
+            oss << ": Filter None";
+            Action::manager().store(oss.str());
+            info.reset();
+        }
 
-    // filter selection
-    std::ostringstream oss;
-    oss << s.name();
-    int type = (int) s.filter()->type();
-    ImGui::SetNextItemWidth(IMGUI_RIGHT_ALIGN);
-    if (ImGuiToolkit::ComboIcon("##SelectFilter", &type, FrameBufferFilter::Types)) {
-        s.setFilter( FrameBufferFilter::Type(type) );
-        oss << ": Filter " << std::get<2>(FrameBufferFilter::Types[type]);
-        Action::manager().store(oss.str());
-        info.reset();
-    }
-    ImGui::SameLine(0, IMGUI_SAME_LINE);
-    if (ImGuiToolkit::TextButton("Filter")) {
-        s.setFilter( FrameBufferFilter::FILTER_PASSTHROUGH );
-        oss << ": Filter None";
-        Action::manager().store(oss.str());
-        info.reset();
-    }
+        // filter options
+        s.filter()->accept(*this);
 
-    // filter options
-    s.filter()->accept(*this);
+        ImVec2 botom = ImGui::GetCursorPos();
 
-    ImVec2 botom = ImGui::GetCursorPos();
-
-    if ( !s.failed() ) {
         // icon (>) to open player
         if ( s.playable() ) {
             ImGui::SetCursorPos(top);
             if (ImGuiToolkit::IconButton(ICON_FA_PLAY_CIRCLE, "Open in Player"))
                 UserInterface::manager().showSourceEditor(&s);
         }
-    }
-    else
-        info.reset();
 
-    ImGui::SetCursorPos(botom);
+        ImGui::SetCursorPos(botom);
+    }
+    else {
+        ImGuiToolkit::ButtonDisabled("No source", ImVec2(IMGUI_RIGHT_ALIGN, 0) );
+        ImGui::SameLine(0, IMGUI_SAME_LINE);
+        ImGui::Text("Origin");
+        info.reset();
+    }
 }
 
 void ImGuiVisitor::visit (PatternSource& s)
@@ -1254,25 +1252,26 @@ void ImGuiVisitor::visit (DeviceSource& s)
     ImGui::Text("%s", info.str().c_str());
     ImGui::PopTextWrapPos();
 
-    ImGui::SetNextItemWidth(IMGUI_RIGHT_ALIGN);
-    if (ImGui::BeginCombo("Device", s.device().c_str()))
-    {
-        for (int d = 0; d < Device::manager().numDevices(); ++d){
-            std::string namedev = Device::manager().name(d);
-            if (ImGui::Selectable( namedev.c_str() )) {
-                s.setDevice(namedev);
-                info.reset();
-                std::ostringstream oss;
-                oss << s.name() << " Device " << namedev;
-                Action::manager().store(oss.str());
-            }
-        }
-        ImGui::EndCombo();
-    }
-
     ImVec2 botom = ImGui::GetCursorPos();
 
     if ( !s.failed() ) {
+
+        ImGui::SetNextItemWidth(IMGUI_RIGHT_ALIGN);
+        if (ImGui::BeginCombo("Device", s.device().c_str()))
+        {
+            for (int d = 0; d < Device::manager().numDevices(); ++d){
+                std::string namedev = Device::manager().name(d);
+                if (ImGui::Selectable( namedev.c_str() )) {
+                    s.setDevice(namedev);
+                    info.reset();
+                    std::ostringstream oss;
+                    oss << s.name() << " Device " << namedev;
+                    Action::manager().store(oss.str());
+                }
+            }
+            ImGui::EndCombo();
+        }
+
         // icon (>) to open player
         if ( s.playable() ) {
             ImGui::SetCursorPos(top);
@@ -1427,21 +1426,22 @@ void ImGuiVisitor::visit (GenericStreamSource& s)
     ImGui::Text("%s", info.str().c_str());
     ImGui::PopTextWrapPos();
 
-    // Prepare display pipeline text
-    static int numlines = 0;
-    const ImGuiContext& g = *GImGui;
-    ImVec2 fieldsize(w,  MAX(3, numlines) * g.FontSize + g.Style.ItemSpacing.y + g.Style.FramePadding.y);
-
-    // Editor
-    std::string _description = s.description();
-    if ( ImGuiToolkit::InputCodeMultiline("Pipeline", &_description, fieldsize, &numlines) ) {
-        s.setDescription(_description);
-        Action::manager().store( s.name() + ": Change pipeline");
-    }
-
     ImVec2 botom = ImGui::GetCursorPos();
 
     if ( !s.failed() ) {
+
+        // Prepare display pipeline text
+        static int numlines = 0;
+        const ImGuiContext& g = *GImGui;
+        ImVec2 fieldsize(w,  MAX(3, numlines) * g.FontSize + g.Style.ItemSpacing.y + g.Style.FramePadding.y);
+
+        // Editor
+        std::string _description = s.description();
+        if ( ImGuiToolkit::InputCodeMultiline("Pipeline", &_description, fieldsize, &numlines) ) {
+            s.setDescription(_description);
+            Action::manager().store( s.name() + ": Change pipeline");
+        }
+
         // icon (>) to open player
         if ( s.playable() ) {
             ImGui::SetCursorPos(top);
diff --git a/src/MediaSource.cpp b/src/MediaSource.cpp
index 1a6ee83..5dfa020 100644
--- a/src/MediaSource.cpp
+++ b/src/MediaSource.cpp
@@ -78,9 +78,9 @@ std::string MediaSource::info() const
         return "Video File";
 }
 
-bool MediaSource::failed() const
+Source::Failure MediaSource::failed() const
 {
-    return mediaplayer_->failed();
+    return mediaplayer_->failed() ? FAIL_CRITICAL : FAIL_NONE;
 }
 
 uint MediaSource::texture() const
diff --git a/src/MediaSource.h b/src/MediaSource.h
index a7bc64a..40ad483 100644
--- a/src/MediaSource.h
+++ b/src/MediaSource.h
@@ -20,7 +20,7 @@ public:
     void replay () override;
     guint64 playtime () const override;
     void render() override;
-    bool failed() const override;
+    Failure failed() const override;
     uint texture() const override;
     void accept (Visitor& v) override;
 
diff --git a/src/Mixer.cpp b/src/Mixer.cpp
index 50a5ab0..413c0bf 100644
--- a/src/Mixer.cpp
+++ b/src/Mixer.cpp
@@ -205,25 +205,37 @@ void Mixer::update()
     FrameGrabbing::manager().grabFrame(session_->frame());
 
     // manage sources which failed update
-    SourceListUnique failures = session()->failedSources();
-    for(auto it = failures.begin(); it != failures.end(); ++it)  {
-        // if the failed source is still attached to the mixer
-        if ( attached( *it ) ) {
-            // special case of failed Render loopback :
-            // it fails when resolution change, and we can fix it by
-            // recreating it in the current session
-            RenderSource *failedRender = dynamic_cast<RenderSource *>(*it);
-            if (failedRender != nullptr) {
-                // try to recreate the failed render source
-                if ( !recreateSource(failedRender) )
-                    // delete the source if could not
-                    deleteSource(failedRender);
+    if (session_->ready()) {
+        // go through all failed sources
+        SourceListUnique _failedsources = session_->failedSources();
+        for(auto it = _failedsources.begin(); it != _failedsources.end(); ++it)  {
+            // only deal with sources that are still attached to mixer
+            if ( attached( *it ) ) {
+                // intervention depends on the severity of the failure
+                Source::Failure fail = (*it)->failed();
+                // Attempt to repair BAD failed sources
+                // (can be automatically repaired without user intervention)
+                if (fail == Source::FAIL_BAD) {
+                    if ( !recreateSource( *it ) ) {
+                        Log::Warning("Source '%s' failed and was deleted.", (*it)->name().c_str());
+                        // delete failed source if could not recreate it
+                        deleteSource( *it );
+                    }
+                }
+                // Detatch CRITICAL failed sources from the mixer
+                // (not deleted in the session; user can replace it)
+                else if (fail == Source::FAIL_CRITICAL) {
+                    detach( *it );
+                }
+                // Delete FATAL failed sources from the mixer
+                // (nothing can be done by the user)
+                else {
+                    Log::Warning("Source '%s' failed and was deleted.", (*it)->name().c_str());
+                    deleteSource( *it );
+                }
+                // needs refresh after intervention
+                ++View::need_deep_update_;
             }
-            // general case:
-            // detatch failed sources from the mixer
-            // (not deleted in the session; user can replace it)
-            else
-                detach( *it );
         }
     }
 
diff --git a/src/RenderSource.cpp b/src/RenderSource.cpp
index c296d9d..be5f7be 100644
--- a/src/RenderSource.cpp
+++ b/src/RenderSource.cpp
@@ -47,12 +47,12 @@ RenderSource::~RenderSource()
         delete rendered_output_;
 }
 
-bool RenderSource::failed() const
+Source::Failure RenderSource::failed() const
 {
     if ( rendered_output_ != nullptr && session_ != nullptr )
-        return rendered_output_->resolution() != session_->frame()->resolution();
+        return rendered_output_->resolution() != session_->frame()->resolution() ? FAIL_BAD : FAIL_NONE;
 
-    return false;
+    return FAIL_NONE;
 }
 
 uint RenderSource::texture() const
diff --git a/src/RenderSource.h b/src/RenderSource.h
index 8899a22..b9a9987 100644
--- a/src/RenderSource.h
+++ b/src/RenderSource.h
@@ -18,7 +18,7 @@ public:
     void replay () override {}
     bool playable () const  override { return true; }
     guint64 playtime () const override { return runtime_; }
-    bool failed () const override;
+    Failure failed () const override;
     uint texture() const override;
     void accept (Visitor& v) override;
 
diff --git a/src/Session.cpp b/src/Session.cpp
index b8536d2..edcca81 100644
--- a/src/Session.cpp
+++ b/src/Session.cpp
@@ -44,7 +44,7 @@ SessionNote::SessionNote(const std::string &t, bool l, int s): label(std::to_str
 }
 
 Session::Session(uint64_t id) : id_(id), active_(true), activation_threshold_(MIXING_MIN_THRESHOLD),
-    filename_(""), thumbnail_(nullptr)
+    filename_(""), thumbnail_(nullptr), ready_(false)
 {
     // create unique id
     if (id_ == 0)
@@ -138,6 +138,14 @@ void Session::setActive (bool on)
     }
 }
 
+
+void Session::deleteFailedSources ()
+{
+    while (!failed_.empty()) {
+        deleteSource( *(failed_.begin()) );
+    }
+}
+
 // update all sources
 void Session::update(float dt)
 {
@@ -234,7 +242,7 @@ void Session::update(float dt)
     }
 
     // pre-render all sources
-    bool ready = true;
+    ready_ = true;
     for( SourceList::iterator it = sources_.begin(); it != sources_.end(); ++it){
 
         // ensure the RenderSource is rendering *this* session
@@ -244,17 +252,20 @@ void Session::update(float dt)
 
         // discard failed source
         if ( (*it)->failed() ) {
-            // insert source in list of failed
-            // (NB: insert in set fails if source is already listed)
-            failed_.insert( *it );
-            // do not render
-            render_.scene.ws()->detach( (*it)->group(View::RENDERING) );
+            // if source is already attached
+            if ((*it)->group(View::RENDERING)->refcount_ > 0) {
+                // insert source in list of failed
+                // (NB: insert in set fails if source is already listed)
+                failed_.insert( *it );
+                // detatch from rendering (do not render)
+                render_.scene.ws()->detach( (*it)->group(View::RENDERING) );
+            }
         }
         // render normally
         else {
             // session is not ready if one source is not ready
             if ( !(*it)->ready() )
-                ready = false;
+                ready_ = false;
             // update the source
             (*it)->setActive(activation_threshold_);
             (*it)->update(dt);
@@ -307,7 +318,7 @@ void Session::update(float dt)
     render_.draw();
 
     // draw the thumbnail only after all sources are ready
-    if (ready)
+    if (ready_)
         render_.drawThumbnail();
 }
 
@@ -589,9 +600,9 @@ bool Session::canlink (SourceList sources)
     validate(sources);
 
     for (auto it = sources.begin(); it != sources.end(); ++it) {
-        // this source is linked
+        // if this source is linked
         if ( (*it)->mixingGroup() != nullptr ) {
-            // askt its group to detach it
+            // ask its group to detach it
             canlink = false;
         }
     }
diff --git a/src/Session.h b/src/Session.h
index 7797eaa..f7ac14d 100644
--- a/src/Session.h
+++ b/src/Session.h
@@ -88,6 +88,7 @@ public:
     uint numSources() const;
 
     // update all sources and mark sources which failed
+    inline bool ready () const  { return ready_; }
     void update (float dt);
     uint64_t runtime() const;
 
@@ -97,6 +98,7 @@ public:
 
     // return the list of sources which failed
     SourceListUnique failedSources () const { return failed_; }
+    void deleteFailedSources ();
 
     // get frame result of render
     inline FrameBuffer *frame () const { return render_.frame(); }
@@ -195,6 +197,7 @@ protected:
     std::mutex access_;
     FrameBufferImage *thumbnail_;
     uint64_t start_time_;
+    bool ready_;
 
     struct Fading
     {
diff --git a/src/SessionSource.cpp b/src/SessionSource.cpp
index 0213a12..3694dc8 100644
--- a/src/SessionSource.cpp
+++ b/src/SessionSource.cpp
@@ -113,9 +113,9 @@ Session *SessionSource::detach()
     return giveaway;
 }
 
-bool SessionSource::failed() const
+Source::Failure SessionSource::failed() const
 {
-    return failed_;
+    return failed_ ? FAIL_CRITICAL : FAIL_NONE;
 }
 
 uint SessionSource::texture() const
@@ -149,15 +149,9 @@ void SessionSource::update(float dt)
         timer_ += guint64(dt * 1000.f) * GST_USECOND;
     }
 
-    // delete source which failed
-    if ( !session_->failedSources().empty() ) {
-        Source *failure = *(session_->failedSources().cbegin());
-        Log::Info("Source '%s' deleted from Child Session %s.", failure->name().c_str(), std::to_string(session_->id()).c_str());
-        session_->deleteSource( failure );
-        // fail session if all sources failed
-        if ( session_->size() < 1)
-            failed_ = true;
-    }
+    // fail session if all its sources failed
+    if ( session_->failedSources().size() == session_->size() )
+        failed_ = true;
 
 }
 
diff --git a/src/SessionSource.h b/src/SessionSource.h
index 3f8bc42..86eec92 100644
--- a/src/SessionSource.h
+++ b/src/SessionSource.h
@@ -19,7 +19,7 @@ public:
     bool playable () const  override;
     guint64 playtime () const override { return timer_; }
     void replay () override;
-    bool failed () const override;
+    Failure failed () const override;
     uint texture () const override;
 
     Session *detach();
diff --git a/src/Source.h b/src/Source.h
index d166d99..5214842 100644
--- a/src/Source.h
+++ b/src/Source.h
@@ -177,7 +177,13 @@ public:
     virtual guint64 playtime () const { return 0; }
 
     // a Source shall informs if the source failed (i.e. shall be deleted)
-    virtual bool failed () const = 0;
+    typedef enum {
+        FAIL_NONE = 0,
+        FAIL_BAD= 1,
+        FAIL_CRITICAL = 2,
+        FAIL_FATAL  = 3
+    } Failure;
+    virtual Failure failed () const = 0;
 
     // a Source shall define a way to get a texture
     virtual uint texture () const = 0;
@@ -251,7 +257,7 @@ public:
     }
 
     static bool isInitialized (const Source* elem)  {
-        return (elem && elem->mode_ > Source::UNINITIALIZED);
+        return (elem && ( elem->mode_ > Source::UNINITIALIZED || elem->failed() ) );
     }
 
     // class-dependent icon
diff --git a/src/SourceList.cpp b/src/SourceList.cpp
index 6d10308..69c9815 100644
--- a/src/SourceList.cpp
+++ b/src/SourceList.cpp
@@ -46,7 +46,7 @@ SourceList playable_only (const SourceList &list)
 }
 
 
-bool isfailed (const Source *s) { return s->failed(); }
+bool isfailed (const Source *s) { return s->failed() != Source::FAIL_NONE; }
 
 SourceList valid_only (const SourceList &list)
 {
diff --git a/src/StreamSource.cpp b/src/StreamSource.cpp
index aca0d35..c1471bc 100644
--- a/src/StreamSource.cpp
+++ b/src/StreamSource.cpp
@@ -93,9 +93,9 @@ StreamSource::~StreamSource()
         delete stream_;
 }
 
-bool StreamSource::failed() const
+Source::Failure StreamSource::failed() const
 {
-    return (stream_ != nullptr &&  stream_->failed() );
+    return (stream_ != nullptr &&  stream_->failed()) ? FAIL_CRITICAL : FAIL_NONE;
 }
 
 uint StreamSource::texture() const
diff --git a/src/StreamSource.h b/src/StreamSource.h
index 870e476..18ed873 100644
--- a/src/StreamSource.h
+++ b/src/StreamSource.h
@@ -35,7 +35,7 @@ public:
     bool playable () const  override;
     void replay () override;
     guint64 playtime () const override;
-    bool failed() const override;
+    Failure failed() const override;
     uint texture() const override;
 
     // pure virtual interface