added more verbose error handling in the console output

demo/index.js

@@ -9,6 +9,8 @@ import { OpenSheetMusicDisplay } from '../src/OpenSheetMusicDisplay/OpenSheetMus
     // The available demos
         demos = {
             "Beethoven - An die ferne Geliebte": "Beethoven_AnDieFerneGeliebte.xml",
+            "NinskaBanja_LoosMeasures.xml": "NinskaBanja_LoosMeasures.xml",
+            "NiskaBanja_DoesNotRender": "NiskaBanja_DoesNotRender.xml",
             "M. Clementi - Sonatina Op.36 No.1 Pt.1": "MuzioClementi_SonatinaOpus36No1_Part1.xml",
             "M. Clementi - Sonatina Op.36 No.1 Pt.2": "MuzioClementi_SonatinaOpus36No1_Part2.xml",
             "M. Clementi - Sonatina Op.36 No.3 Pt.1": "MuzioClementi_SonatinaOpus36No3_Part1.xml",
@@ -82,7 +84,6 @@ import { OpenSheetMusicDisplay } from '../src/OpenSheetMusicDisplay/OpenSheetMus
         select.onchange = selectOnChange;
 
         // Pre-select default music piece
-        select.value = "MuzioClementi_SonatinaOpus36No1_Part1.xml";
 
         custom.appendChild(document.createTextNode("Custom"));
 
@@ -187,6 +188,7 @@ import { OpenSheetMusicDisplay } from '../src/OpenSheetMusicDisplay/OpenSheetMus
                 return openSheetMusicDisplay.render();
             },
             function(e) {
+                console.warn(e.stack);
                 error("Error reading sheet: " + e);
             }
         ).then(