diff --git a/Modules/CppRestSdk/src/mitkDICOMWeb.cpp b/Modules/CppRestSdk/src/mitkDICOMWeb.cpp
index cbfb84248a..1ebf50b845 100644
--- a/Modules/CppRestSdk/src/mitkDICOMWeb.cpp
+++ b/Modules/CppRestSdk/src/mitkDICOMWeb.cpp
@@ -1,128 +1,131 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #include "mitkDICOMWeb.h"
 #include "mitkRESTUtil.h"
 #include <mitkCommon.h>
 
 mitk::DICOMWeb::DICOMWeb(utility::string_t url) : mitk::RESTClient(url)
 {
 }
 
 mitk::DICOMWeb::~DICOMWeb() 
 {
 }
 
 pplx::task<web::json::value> mitk::DICOMWeb::QuidoRSInstances(std::map<std::string, std::string> params)
 {
   MitkUriBuilder queryBuilder(U("rs/instances"));
 
   for (auto const& element : params)
   {
     queryBuilder.append_query(mitk::RESTUtil::convertToTString(element.first), mitk::RESTUtil::convertToTString(element.second));
   }
 
   MITK_INFO << utility::conversions::to_utf8string(queryBuilder.to_string());
   MitkRequest instances(MitkRESTMethods::GET);
   instances.set_request_uri(queryBuilder.to_string());
   instances.headers().add(U("Accept"), U("application/json"));
 
   return m_Client->request(instances).then([=](MitkResponse response)
   {
     auto status = response.status_code();
     MITK_INFO << " status: " << status;
 
     if (status != web::http::status_codes::OK) {
       mitkThrow() << "QUIDO-RS ended up with response " << mitk::RESTUtil::convertToUtf8(response.to_string());
     }
 
     return response.extract_json().get();
   });
 }
 
 pplx::task<void> mitk::DICOMWeb::WadoRS(utility::string_t filePath, std::string studyUID, std::string seriesUID, std::string instanceUID)
 {
   MitkUriBuilder builder(U("wado"));
   builder.append_query(U("requestType"), U("WADO"));
   builder.append_query(U("studyUID"), mitk::RESTUtil::convertToTString(studyUID));
   builder.append_query(U("seriesUID"), mitk::RESTUtil::convertToTString(seriesUID));
   builder.append_query(U("objectUID"), mitk::RESTUtil::convertToTString(instanceUID));
   builder.append_query(U("contentType"), U("application/dicom"));
   return Get(filePath, builder.to_string());
 }
 
 pplx::task<std::string> mitk::DICOMWeb::WadoRS(const utility::string_t folderPath, std::string studyUID, std::string seriesUID)
 {
   typedef std::map<std::string, std::string> ParamMap;
   ParamMap seriesInstancesParams;
 
   seriesInstancesParams.insert(ParamMap::value_type({"StudyInstanceUID"}, studyUID));
   seriesInstancesParams.insert(ParamMap::value_type({"SeriesInstanceUID"}, seriesUID));
 
   return QuidoRSInstances(seriesInstancesParams).then([=](web::json::value jsonResult) -> pplx::task<std::string>
   {
     auto jsonListResult = jsonResult;
     auto resultArray = jsonListResult.as_array();
 
     auto firstFileName = std::string();
 
     std::vector<pplx::task<void>> tasks;
 
     for (unsigned short i = 0; i < resultArray.size(); i++)
     {
       try
       {
         auto firstResult = resultArray[i];
         auto sopInstanceUIDKey = firstResult.at(U("00080018"));
         auto sopInstanceObject = sopInstanceUIDKey.as_object();
         auto valueKey = sopInstanceObject.at(U("Value"));
         auto valueArray = valueKey.as_array();
         auto sopInstanceUID = valueArray[0].as_string();
 
         auto fileName = utility::string_t(sopInstanceUID).append(U(".dcm"));
 
         // save first file name as result to load series
         if (i == 0)
         {
           firstFileName = utility::conversions::to_utf8string(fileName);
         }
 
         auto filePath = utility::string_t(folderPath).append(fileName);
         auto task = WadoRS(filePath, studyUID, seriesUID, mitk::RESTUtil::convertToUtf8(sopInstanceUID));
         tasks.push_back(task);
       }
       catch (const web::json::json_exception& e)
       {
         MITK_ERROR << e.what();
       }
     }
 
     auto joinTask = pplx::when_all(begin(tasks), end(tasks));
-    return joinTask.then([=](void)
+
+    auto returnTask = joinTask.then([=](void) -> std::string
     {
       return utility::conversions::to_utf8string(folderPath).append(firstFileName);
     });
+
+    return returnTask;
   });
 }
 
 pplx::task<void> mitk::DICOMWeb::StowRS(utility::string_t filePath, std::string studyUID)
 {
   // TODO: add data
   MitkUriBuilder builder(U("rs/studies"));
   builder.append_path(mitk::RESTUtil::convertToTString(studyUID));
 
   return Post(builder.to_string(), U("multipart/related; type='application/dicom'; boundary='boundary'"), filePath);
 }
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