diff --git a/pcbnew/router/router_tool.cpp b/pcbnew/router/router_tool.cpp
index 6456229e87..2fb9a5fdcd 100644
--- a/pcbnew/router/router_tool.cpp
+++ b/pcbnew/router/router_tool.cpp
@@ -2,7 +2,7 @@
  * KiRouter - a push-and-(sometimes-)shove PCB router
  *
  * Copyright (C) 2013-2017 CERN
- * Copyright (C) 2016 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2017 KiCad Developers, see AUTHORS.txt for contributors.
  * Author: Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
  *
  * This program is free software: you can redistribute it and/or modify it
@@ -146,49 +146,57 @@ public:
 
     OPT_TOOL_EVENT EventHandler( const wxMenuEvent& aEvent )
     {
-#if ID_POPUP_PCB_SELECT_VIASIZE1 < ID_POPUP_PCB_SELECT_WIDTH1
-#error You have changed event ids order, it breaks code. Check the source code for more details.
-// Recognising type of event (track width/via size) is based on comparison if the event id is
-// within a specific range. If ranges of event ids changes, then the following is not valid anymore.
-#endif
         BOARD_DESIGN_SETTINGS &bds = m_board->GetDesignSettings();
-
         int id = aEvent.GetId();
 
-        // Initial settings, to be modified below
-        bds.m_UseConnectedTrackWidth = false;
-        bds.UseCustomTrackViaSize( false );
+        // On Windows, this handler can be called with a  non existing event ID not existing
+        // in any menuitem.
+        // So we keep trace of in-range/out-of-range event ID
+        bool in_range = true;
+
+        // Initial settings, to be modified below, but only if the ID exists in this menu
+        bool useConnectedTrackWidth = false;
+        bool useCustomTrackViaSize = false;
 
         if( id == ID_POPUP_PCB_SELECT_CUSTOM_WIDTH )
         {
-            bds.UseCustomTrackViaSize( true );
+            useCustomTrackViaSize = true;
         }
-
         else if( id == ID_POPUP_PCB_SELECT_AUTO_WIDTH )
         {
-            bds.m_UseConnectedTrackWidth = true;
+            useConnectedTrackWidth = true;
         }
-
         else if( id == ID_POPUP_PCB_SELECT_USE_NETCLASS_VALUES )
         {
             bds.SetViaSizeIndex( 0 );
             bds.SetTrackWidthIndex( 0 );
         }
-
-        else if( id >= ID_POPUP_PCB_SELECT_VIASIZE1 )     // via size has changed
+        else if( id >= ID_POPUP_PCB_SELECT_VIASIZE1 &&
+                 id <= ID_POPUP_PCB_SELECT_VIASIZE16 )
         {
-            assert( id < ID_POPUP_PCB_SELECT_WIDTH_END_RANGE );
-
+           // via size has changed
             bds.SetViaSizeIndex( id - ID_POPUP_PCB_SELECT_VIASIZE1 );
         }
-
-        else    // track width has changed
+        else if( id >= ID_POPUP_PCB_SELECT_WIDTH1 &&
+                 id <= ID_POPUP_PCB_SELECT_WIDTH16 )
         {
-            assert( id >= ID_POPUP_PCB_SELECT_WIDTH1 );
-            assert( id < ID_POPUP_PCB_SELECT_VIASIZE );
-
+            // track width has changed
             bds.SetTrackWidthIndex( id - ID_POPUP_PCB_SELECT_WIDTH1 );
         }
+        else
+        {
+            in_range = false;   // This event ID does not exist in the menu
+            wxASSERT_MSG( false, "OPT_TOOL_EVENT EventHandler: unexpected id" );
+            // Fix me: How to return this error as OPT_TOOL_EVENT?
+        }
+
+        if( in_range )
+        {
+            // Update this setup only id the event ID matches the options of this menu
+            bds.m_UseConnectedTrackWidth = useConnectedTrackWidth;
+            bds.UseCustomTrackViaSize( useCustomTrackViaSize );
+        }
+
 
         return OPT_TOOL_EVENT( COMMON_ACTIONS::trackViaSizeChanged.MakeEvent() );
     }