diff --git a/gerbview/excellon_read_drill_file.cpp b/gerbview/excellon_read_drill_file.cpp
index 85c4016b06..1efe8e05d4 100644
--- a/gerbview/excellon_read_drill_file.cpp
+++ b/gerbview/excellon_read_drill_file.cpp
@@ -247,36 +247,33 @@ bool GERBVIEW_FRAME::Read_EXCELLON_File( const wxString& aFullFileName )
     int layerId = GetActiveLayer();      // current layer used in GerbView
     GERBER_FILE_IMAGE_LIST* images = GetGerberLayout()->GetImagesList();
     auto gerber_layer = images->GetGbrImage( layerId );
-    auto drill_layer = dynamic_cast<EXCELLON_IMAGE*>( gerber_layer );
 
-    if( gerber_layer && !drill_layer )
-    {
-        // The active layer contains old gerber data we have to clear
+    // OIf the active layer contains old gerber or nc drill data, remove it
+    if( gerber_layer )
         Erase_Current_DrawLayer( false );
-    }
 
-    if( drill_layer == nullptr )
-    {
-        drill_layer = new EXCELLON_IMAGE( layerId );
-        layerId = images->AddGbrImage( drill_layer, layerId );
-    }
-
-    if( layerId < 0 )
-    {
-        DisplayError( this, _( "No room to load file" ) );
-        return false;
-    }
+    EXCELLON_IMAGE* drill_layer = new EXCELLON_IMAGE( layerId );
 
     // Read the Excellon drill file:
     bool success = drill_layer->LoadFile( aFullFileName );
 
     if( !success )
     {
-        msg.Printf( _( "File %s not found" ), GetChars( aFullFileName ) );
+        delete drill_layer;
+        msg.Printf( _( "File %s not found" ), aFullFileName );
         DisplayError( this, msg );
         return false;
     }
 
+    layerId = images->AddGbrImage( drill_layer, layerId );
+
+    if( layerId < 0 )
+    {
+        delete drill_layer;
+        DisplayError( this, _( "No room to load file" ) );
+        return false;
+    }
+
     // Display errors list
     if( drill_layer->GetMessages().size() > 0 )
     {
diff --git a/gerbview/files.cpp b/gerbview/files.cpp
index 752afd7004..4eeaf621c2 100644
--- a/gerbview/files.cpp
+++ b/gerbview/files.cpp
@@ -284,6 +284,24 @@ bool GERBVIEW_FRAME::loadListOfGerberAndDrillFiles( const wxString& aPath,
 
     for( unsigned ii = 0; ii < aFilenameList.GetCount(); ii++ )
     {
+
+        filename = aFilenameList[ii];
+
+        if( !filename.IsAbsolute() )
+            filename.SetPath( aPath );
+
+        // Check for non existing files, to avoid creating broken or useless data
+        // and report all in one error list:
+        if( !filename.FileExists() )
+        {
+            wxString warning;
+            warning << "<b>" << _( "File not found:" ) << "</b><br>"
+                    << filename.GetFullPath() << "<br>";
+            reporter.Report( warning, REPORTER::RPT_WARNING );
+            success = false;
+            continue;
+        }
+
         if( !progress && wxGetUTCTimeMillis() - startTime > progressShowDelay )
         {
             progress = std::make_unique<WX_PROGRESS_REPORTER>( this,
@@ -296,11 +314,6 @@ bool GERBVIEW_FRAME::loadListOfGerberAndDrillFiles( const wxString& aPath,
             progress->KeepRefreshing();
         }
 
-        filename = aFilenameList[ii];
-
-        if( !filename.IsAbsolute() )
-            filename.SetPath( aPath );
-
         m_lastFileName = filename.GetFullPath();
 
         SetActiveLayer( layer, false );
diff --git a/gerbview/gerber_file_image_list.cpp b/gerbview/gerber_file_image_list.cpp
index b6135c1b02..6e81336477 100644
--- a/gerbview/gerber_file_image_list.cpp
+++ b/gerbview/gerber_file_image_list.cpp
@@ -117,7 +117,7 @@ void GERBER_FILE_IMAGE_LIST::DeleteImage( int aIdx )
     GERBER_FILE_IMAGE* gbr_image = GetGbrImage( aIdx );
 
     delete gbr_image;
-    m_GERBER_List[ aIdx ] = NULL;
+    m_GERBER_List[ aIdx ] = nullptr;
 }
 
 // Build a name for image aIdx which can be used in layers manager
diff --git a/gerbview/gerbview_frame.cpp b/gerbview/gerbview_frame.cpp
index 983c873941..0dc0a2f027 100644
--- a/gerbview/gerbview_frame.cpp
+++ b/gerbview/gerbview_frame.cpp
@@ -249,8 +249,8 @@ GERBVIEW_FRAME::~GERBVIEW_FRAME()
 
 void GERBVIEW_FRAME::OnCloseWindow( wxCloseEvent& Event )
 {
-    GetGalCanvas()->GetView()->Clear();
     GetGalCanvas()->StopDrawing();
+    GetGalCanvas()->GetView()->Clear();
 
     if( m_toolManager )
         m_toolManager->DeactivateTool();
diff --git a/gerbview/readgerb.cpp b/gerbview/readgerb.cpp
index d36d6acfd6..23265ab06b 100644
--- a/gerbview/readgerb.cpp
+++ b/gerbview/readgerb.cpp
@@ -51,18 +51,21 @@ bool GERBVIEW_FRAME::Read_GERBER_File( const wxString& GERBER_FullFileName )
     }
 
     gerber = new GERBER_FILE_IMAGE( layer );
-    images->AddGbrImage( gerber, layer );
 
-    /* Read the gerber file */
+    // Read the gerber file. The image will be added only if it can be read
+    // to avoid broken data.
     bool success = gerber->LoadGerberFile( GERBER_FullFileName );
 
     if( !success )
     {
-        msg.Printf( _( "File \"%s\" not found" ), GetChars( GERBER_FullFileName ) );
+        delete gerber;
+        msg.Printf( _( "File \"%s\" not found" ), GERBER_FullFileName );
         DisplayError( this, msg, 10 );
         return false;
     }
 
+    images->AddGbrImage( gerber, layer );
+
     // Display errors list
     if( gerber->GetMessages().size() > 0 )
     {