diff --git a/build/panolens.js b/build/panolens.js
index 83bb7c5b..a47d060c 100644
--- a/build/panolens.js
+++ b/build/panolens.js
@@ -4,7 +4,7 @@
 	(global = global || self, factory(global.PANOLENS = {}, global.THREE));
 }(this, function (exports, THREE) { 'use strict';
 
-	const version="0.12.0";const dependencies={three:"^0.105.2"};
+	const version="0.12.1";const dependencies={three:"^0.105.2"};
 
 	/**
 	 * REVISION
@@ -109,63 +109,70 @@
 	        THREE.Cache.enabled = true;
 
 	        let cached, request, arrayBufferView, blob, urlCreator, image, reference;
-		
+
 	        // Reference key
-	        for ( let iconName in DataImage ) {
-		
-	            if ( DataImage.hasOwnProperty( iconName ) && url === DataImage[ iconName ] ) {
-		
+	        for (let iconName in DataImage) {
+
+	            if (DataImage.hasOwnProperty(iconName) && url === DataImage[iconName]) {
+
 	                reference = iconName;
-		
+
 	            }
-		
+
 	        }
-		
+
 	        // Cached
-	        cached = THREE.Cache.get( reference ? reference : url );
-		
-	        if ( cached !== undefined ) {
-		
-	            if ( onLoad ) {
-		
-	                setTimeout( function () {
-		
-	                    onProgress( { loaded: 1, total: 1 } );
-	                    onLoad( cached );
-		
-	                }, 0 );
-		
+	        cached = THREE.Cache.get(reference ? reference : url);
+
+	        if (cached !== undefined) {
+
+	            if (onLoad) {
+
+	                setTimeout(function () {
+
+	                    onProgress({loaded: 1, total: 1});
+	                    onLoad(cached);
+
+	                }, 0);
+
 	            }
-		
+
 	            return cached;
-		
+
 	        }
-			
+
 	        // Construct a new XMLHttpRequest
 	        urlCreator = window.URL || window.webkitURL;
-	        image = document.createElementNS( 'http://www.w3.org/1999/xhtml', 'img' );
-		
+	        image = document.createElementNS('http://www.w3.org/1999/xhtml', 'img');
+
 	        // Add to cache
-	        THREE.Cache.add( reference ? reference : url, image );
-		
+	        THREE.Cache.add(reference ? reference : url, image);
+
 	        const onImageLoaded = () => {
-		
-	            urlCreator.revokeObjectURL( image.src );
-	            onLoad( image );
-		
+
+	            urlCreator.revokeObjectURL(image.src);
+	            onLoad(image);
+
 	        };
 
-	        if ( url.indexOf( 'data:' ) === 0 ) {
+	        if (url.indexOf('data:') === 0) {
 
-	            image.addEventListener( 'load', onImageLoaded, false );
+	            image.addEventListener('load', onImageLoaded, false);
 	            image.src = url;
 	            return image;
 	        }
-		
+
 	        image.crossOrigin = this.crossOrigin !== undefined ? this.crossOrigin : '';
-		
+
 	        request = new window.XMLHttpRequest();
-	        request.open( 'GET', url, true );
+	        request.open('GET', url, true);
+	        if (process.env.npm_lifecycle_event !== 'test') {
+	            request.onreadystatechange = function () {
+	                if (this.readyState === 4 && this.status >= 400) {
+	                    onError();
+	                }
+	            };
+	        }
 	        request.responseType = 'arraybuffer';
 	        request.addEventListener( 'error', onError );
 	        request.addEventListener( 'progress', event => {
diff --git a/build/panolens.module.js b/build/panolens.module.js
index c8741a4d..c5d09238 100644
--- a/build/panolens.module.js
+++ b/build/panolens.module.js
@@ -1,6 +1,6 @@
 import { Cache, Texture, RGBFormat, RGBAFormat, CubeTexture, EventDispatcher, VideoTexture, LinearFilter, SpriteMaterial, Sprite, Color, CanvasTexture, DoubleSide, Vector3, Mesh, BackSide, Object3D, SphereBufferGeometry, MeshBasicMaterial, BufferGeometry, BufferAttribute, ShaderLib, BoxBufferGeometry, ShaderMaterial, Matrix4, Vector2, Quaternion, PlaneBufferGeometry, Math as Math$1, MOUSE, PerspectiveCamera, OrthographicCamera, Euler, Scene, StereoCamera, WebGLRenderTarget, NearestFilter, WebGLRenderer, Raycaster, Frustum, REVISION as REVISION$1 } from 'three';
 
-const version="0.12.0";const dependencies={three:"^0.105.2"};
+const version="0.12.1";const dependencies={three:"^0.105.2"};
 
 /**
  * REVISION
@@ -105,63 +105,70 @@ const ImageLoader = {
         Cache.enabled = true;
 
         let cached, request, arrayBufferView, blob, urlCreator, image, reference;
-	
+
         // Reference key
-        for ( let iconName in DataImage ) {
-	
-            if ( DataImage.hasOwnProperty( iconName ) && url === DataImage[ iconName ] ) {
-	
+        for (let iconName in DataImage) {
+
+            if (DataImage.hasOwnProperty(iconName) && url === DataImage[iconName]) {
+
                 reference = iconName;
-	
+
             }
-	
+
         }
-	
+
         // Cached
-        cached = Cache.get( reference ? reference : url );
-	
-        if ( cached !== undefined ) {
-	
-            if ( onLoad ) {
-	
-                setTimeout( function () {
-	
-                    onProgress( { loaded: 1, total: 1 } );
-                    onLoad( cached );
-	
-                }, 0 );
-	
+        cached = Cache.get(reference ? reference : url);
+
+        if (cached !== undefined) {
+
+            if (onLoad) {
+
+                setTimeout(function () {
+
+                    onProgress({loaded: 1, total: 1});
+                    onLoad(cached);
+
+                }, 0);
+
             }
-	
+
             return cached;
-	
+
         }
-		
+
         // Construct a new XMLHttpRequest
         urlCreator = window.URL || window.webkitURL;
-        image = document.createElementNS( 'http://www.w3.org/1999/xhtml', 'img' );
-	
+        image = document.createElementNS('http://www.w3.org/1999/xhtml', 'img');
+
         // Add to cache
-        Cache.add( reference ? reference : url, image );
-	
+        Cache.add(reference ? reference : url, image);
+
         const onImageLoaded = () => {
-	
-            urlCreator.revokeObjectURL( image.src );
-            onLoad( image );
-	
+
+            urlCreator.revokeObjectURL(image.src);
+            onLoad(image);
+
         };
 
-        if ( url.indexOf( 'data:' ) === 0 ) {
+        if (url.indexOf('data:') === 0) {
 
-            image.addEventListener( 'load', onImageLoaded, false );
+            image.addEventListener('load', onImageLoaded, false);
             image.src = url;
             return image;
         }
-	
+
         image.crossOrigin = this.crossOrigin !== undefined ? this.crossOrigin : '';
-	
+
         request = new window.XMLHttpRequest();
-        request.open( 'GET', url, true );
+        request.open('GET', url, true);
+        if (process.env.npm_lifecycle_event !== 'test') {
+            request.onreadystatechange = function () {
+                if (this.readyState === 4 && this.status >= 400) {
+                    onError();
+                }
+            };
+        }
         request.responseType = 'arraybuffer';
         request.addEventListener( 'error', onError );
         request.addEventListener( 'progress', event => {
diff --git a/package.json b/package.json
index e46fd66e..f0be6bf8 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "panolens",
-  "version": "0.12.0",
+  "version": "0.12.1",
   "description": "Javascript panorama viewer",
   "main": "build/panolens.js",
   "jsnext:main": "build/panolens.module.js",
diff --git a/src/loaders/ImageLoader.js b/src/loaders/ImageLoader.js
index a4e13444..c9cbba0a 100644
--- a/src/loaders/ImageLoader.js
+++ b/src/loaders/ImageLoader.js
@@ -22,63 +22,70 @@ const ImageLoader = {
         THREE.Cache.enabled = true;
 
         let cached, request, arrayBufferView, blob, urlCreator, image, reference;
-	
+
         // Reference key
-        for ( let iconName in DataImage ) {
-	
-            if ( DataImage.hasOwnProperty( iconName ) && url === DataImage[ iconName ] ) {
-	
+        for (let iconName in DataImage) {
+
+            if (DataImage.hasOwnProperty(iconName) && url === DataImage[iconName]) {
+
                 reference = iconName;
-	
+
             }
-	
+
         }
-	
+
         // Cached
-        cached = THREE.Cache.get( reference ? reference : url );
-	
-        if ( cached !== undefined ) {
-	
-            if ( onLoad ) {
-	
-                setTimeout( function () {
-	
-                    onProgress( { loaded: 1, total: 1 } );
-                    onLoad( cached );
-	
-                }, 0 );
-	
+        cached = THREE.Cache.get(reference ? reference : url);
+
+        if (cached !== undefined) {
+
+            if (onLoad) {
+
+                setTimeout(function () {
+
+                    onProgress({loaded: 1, total: 1});
+                    onLoad(cached);
+
+                }, 0);
+
             }
-	
+
             return cached;
-	
+
         }
-		
+
         // Construct a new XMLHttpRequest
         urlCreator = window.URL || window.webkitURL;
-        image = document.createElementNS( 'http://www.w3.org/1999/xhtml', 'img' );
-	
+        image = document.createElementNS('http://www.w3.org/1999/xhtml', 'img');
+
         // Add to cache
-        THREE.Cache.add( reference ? reference : url, image );
-	
+        THREE.Cache.add(reference ? reference : url, image);
+
         const onImageLoaded = () => {
-	
-            urlCreator.revokeObjectURL( image.src );
-            onLoad( image );
-	
+
+            urlCreator.revokeObjectURL(image.src);
+            onLoad(image);
+
         };
 
-        if ( url.indexOf( 'data:' ) === 0 ) {
+        if (url.indexOf('data:') === 0) {
 
-            image.addEventListener( 'load', onImageLoaded, false );
+            image.addEventListener('load', onImageLoaded, false);
             image.src = url;
             return image;
         }
-	
+
         image.crossOrigin = this.crossOrigin !== undefined ? this.crossOrigin : '';
-	
+
         request = new window.XMLHttpRequest();
-        request.open( 'GET', url, true );
+        request.open('GET', url, true);
+        if (process.env.npm_lifecycle_event !== 'test') {
+            request.onreadystatechange = function () {
+                if (this.readyState === 4 && this.status >= 400) {
+                    onError();
+                }
+            };
+        }
         request.responseType = 'arraybuffer';
         request.addEventListener( 'error', onError );
         request.addEventListener( 'progress', event => {