diff --git a/lib/SendSafely.js b/lib/SendSafely.js
index 42ec787..8661e3c 100644
--- a/lib/SendSafely.js
+++ b/lib/SendSafely.js
@@ -2899,6 +2899,13 @@ function EncryptAndUploadFile (eventHandler, request) {
       let files = [];
       myself.addEncryptionKey(packageId, serverSecret, keyCode);
     function handleResponse(index, parts, files, fileUtil) {
+      if (files[index] === undefined) {
+        myself.eventHandler.raise(myself.SERVER_ERROR_EVENT, {
+          error: 'INTERNAL_ERROR',
+          message: 'getFileIDs: file at index ' + index + ' is undefined'
+        });
+        return;
+      }
       var serverFilename = (files[index].name === undefined) ? myself.defaultFileName : files[index].name;
       myself.responseParser.processAjaxDataRaw(myself.createFileID(packageId, directoryId, files[index], serverFilename, parts, uploadType, myself.async), function (resp) {
         if(resp.response === "SUCCESS") {
@@ -2953,7 +2960,7 @@ function EncryptAndUploadFile (eventHandler, request) {
     }
 
       let _loop = function _loop(i, _p) {
-          _p = _p.then(function (_) {
+          return _p.then(function (_) {
               return new Promise(function (resolve) {
                   let f = filesPath[i];
 
@@ -2968,18 +2975,18 @@ function EncryptAndUploadFile (eventHandler, request) {
                   } else {
                       let fileUtil = new FileUtil({filePath: f, callback: function(){}});
                       fileUtil.init().then(function(file) {
-                          files.push(file);
+                          files[i] = file;
                           handleResponse(i, file.totalParts, files, fileUtil);
                           resolve();
                       });
                   }
               });
           });
-          p = _p;
       };
 
-      for (let i = 0, p = Promise.resolve(); i < filesPath.length; i++) {
-          _loop(i, p);
+      let p = Promise.resolve();
+      for (let i = 0; i < filesPath.length; i++) {
+          p = _loop(i, p);
       }
   };