diff --git a/app/assets/javascripts/app/services/extensionManager.js b/app/assets/javascripts/app/services/extensionManager.js
index 4be7548b3..7d3b926a2 100644
--- a/app/assets/javascripts/app/services/extensionManager.js
+++ b/app/assets/javascripts/app/services/extensionManager.js
@@ -92,6 +92,10 @@ class ExtensionManager {
   */
   retrieveExtensionFromServer(url, callback) {
     this.httpManager.getAbsolute(url, {}, function(response){
+      if(typeof response !== 'object') {
+        callback(null);
+        return;
+      }
       var ext = this.handleExtensionLoadExternalResponseItem(url, response);
       if(callback) {
         callback(ext);