diff --git a/Core/Code/Testing/files.cmake b/Core/Code/Testing/files.cmake
index 1f5a408cb1..6f3ccb8df8 100644
--- a/Core/Code/Testing/files.cmake
+++ b/Core/Code/Testing/files.cmake
@@ -1,155 +1,155 @@
 
 # tests with no extra command line parameter
 set(MODULE_TESTS
   mitkAccessByItkTest.cpp
   mitkCoreObjectFactoryTest.cpp
   mitkMaterialTest.cpp
   mitkActionTest.cpp
   mitkDispatcherTest.cpp
   mitkEnumerationPropertyTest.cpp
   mitkEventTest.cpp
   mitkFocusManagerTest.cpp
   mitkGenericPropertyTest.cpp
   mitkGeometry3DTest.cpp
   mitkGeometryDataToSurfaceFilterTest.cpp
   mitkGlobalInteractionTest.cpp
   mitkImageDataItemTest.cpp
   #mitkImageMapper2DTest.cpp
   mitkImageGeneratorTest.cpp
   mitkBaseDataTest.cpp
   #mitkImageToItkTest.cpp
   mitkImportItkImageTest.cpp
   mitkGrabItkImageMemoryTest.cpp
   mitkInstantiateAccessFunctionTest.cpp
   mitkInteractorTest.cpp
   #mitkITKThreadingTest.cpp
   mitkLevelWindowTest.cpp
   mitkMessageTest.cpp
   #mitkPipelineSmartPointerCorrectnessTest.cpp
   mitkPixelTypeTest.cpp
   mitkPlaneGeometryTest.cpp
   mitkPointSetFileIOTest.cpp
   mitkPointSetTest.cpp
   mitkPointSetWriterTest.cpp
   mitkPointSetReaderTest.cpp
   mitkPointSetInteractorTest.cpp
   mitkPropertyTest.cpp
   mitkPropertyListTest.cpp
   #mitkRegistrationBaseTest.cpp
   #mitkSegmentationInterpolationTest.cpp
   mitkSlicedGeometry3DTest.cpp
   mitkSliceNavigationControllerTest.cpp
   mitkStateMachineTest.cpp
   ##mitkStateMachineContainerTest.cpp ## rewrite test, indirect since no longer exported Bug 14529
   mitkStateTest.cpp
   mitkSurfaceTest.cpp
   mitkSurfaceToSurfaceFilterTest.cpp
   mitkTimeSlicedGeometryTest.cpp
   mitkTransitionTest.cpp
   mitkUndoControllerTest.cpp
   mitkVtkWidgetRenderingTest.cpp
   mitkVerboseLimitedLinearUndoTest.cpp
   mitkWeakPointerTest.cpp
   mitkTransferFunctionTest.cpp
   #mitkAbstractTransformGeometryTest.cpp
   mitkStepperTest.cpp
   itkTotalVariationDenoisingImageFilterTest.cpp
   mitkRenderingManagerTest.cpp
   vtkMitkThickSlicesFilterTest.cpp
   mitkNodePredicateSourceTest.cpp
   mitkVectorTest.cpp
   mitkClippedSurfaceBoundsCalculatorTest.cpp
   mitkExceptionTest.cpp
   mitkExtractSliceFilterTest.cpp
-  #mitkLogTest.cpp
+  mitkLogTest.cpp
   mitkImageDimensionConverterTest.cpp
   mitkLoggingAdapterTest.cpp
   mitkUIDGeneratorTest.cpp
   mitkShaderRepositoryTest.cpp
   mitkPlanePositionManagerTest.cpp
 )
 
 # test with image filename as an extra command line parameter
 set(MODULE_IMAGE_TESTS
   mitkImageTimeSelectorTest.cpp #only runs on images
   mitkImageAccessorTest.cpp #only runs on images
   mitkDataNodeFactoryTest.cpp #runs on all types of data
 )
 
 set(MODULE_SURFACE_TESTS
   mitkSurfaceVtkWriterTest.cpp #only runs on surfaces
   mitkDataNodeFactoryTest.cpp #runs on all types of data
 )
 
 # list of images for which the tests are run
 set(MODULE_TESTIMAGES
   US4DCyl.nrrd
   Pic3D.nrrd
   Pic2DplusT.nrrd
   BallBinary30x30x30.nrrd
   Png2D-bw.png
 )
 set(MODULE_TESTSURFACES
   binary.stl
   ball.stl
 )
 
 set(MODULE_CUSTOM_TESTS
     #mitkLabeledImageToSurfaceFilterTest.cpp
     #mitkExternalToolsTest.cpp
     mitkDataStorageTest.cpp
     mitkDataNodeTest.cpp
     mitkDicomSeriesReaderTest.cpp
     mitkDICOMLocaleTest.cpp
     mitkEventMapperTest.cpp
     mitkEventConfigTest.cpp
     mitkNodeDependentPointSetInteractorTest.cpp
     mitkStateMachineFactoryTest.cpp
     mitkPointSetLocaleTest.cpp
     mitkImageTest.cpp
     mitkImageWriterTest.cpp
     mitkImageVtkMapper2DTest.cpp
     mitkImageVtkMapper2DLevelWindowTest.cpp
     mitkImageVtkMapper2DOpacityTest.cpp
     mitkImageVtkMapper2DResliceInterpolationPropertyTest.cpp
     mitkImageVtkMapper2DColorTest.cpp
     mitkImageVtkMapper2DReinitTest.cpp
     mitkImageVtkMapper2DSwivelTest.cpp
     mitkImageVtkMapper2DTransferFunctionTest.cpp
     mitkIOUtilTest.cpp
     mitkSurfaceVtkMapper3DTest
     mitkSurfaceVtkMapper3DTexturedSphereTest.cpp
     mitkSurfaceGLMapper2DColorTest.cpp
     mitkSurfaceGLMapper2DOpacityTest.cpp
     mitkVolumeCalculatorTest.cpp
     mitkLevelWindowManagerTest.cpp
     mitkPointSetVtkMapper2DTest.cpp
     mitkPointSetVtkMapper2DImageTest.cpp
     mitkPointSetVtkMapper2DGlyphTypeTest.cpp
 )
 
 set(MODULE_RESOURCE_FILES
   Interactions/AddAndRemovePoints.xml
   Interactions/globalConfig.xml
   Interactions/StatemachineTest.xml
   Interactions/StatemachineConfigTest.xml
 )
 
 # Create an artificial module initializing class for
 # the usServiceListenerTest.cpp
 usFunctionGenerateModuleInit(testdriver_init_file
                              NAME ${MODULE_NAME}TestDriver
                              DEPENDS "Mitk"
                              VERSION "0.1.0"
                              EXECUTABLE
                             )
 
 # Embed the resources
 set(testdriver_resources )
 usFunctionEmbedResources(testdriver_resources
                          EXECUTABLE_NAME ${MODULE_NAME}TestDriver
                          ROOT_DIR ${CMAKE_CURRENT_SOURCE_DIR}/Resources
                          FILES ${MODULE_RESOURCE_FILES}
                         )
 
 set(TEST_CPP_FILES ${testdriver_init_file} ${testdriver_resources})
diff --git a/Core/Code/Testing/mitkLogTest.cpp b/Core/Code/Testing/mitkLogTest.cpp
index 6ce6e6c6f6..65fe886844 100644
--- a/Core/Code/Testing/mitkLogTest.cpp
+++ b/Core/Code/Testing/mitkLogTest.cpp
@@ -1,285 +1,286 @@
 /*===================================================================
 
 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 "mitkCommon.h"
 #include "mitkTestingMacros.h"
 #include <mitkLog.h>
 #include <mitkVector.h>
 #include <itkMultiThreader.h>
 #include <itksys/SystemTools.hxx>
 #include <mitkStandardFileLocations.h>
 
 
 /** Documentation
   *
   * @brief Objects of this class can start an internal thread by calling the Start() method.
   *        The thread is then logging messages until the method Stop() is called. The class
   *        can be used to test if logging is thread-save by using multiple objects and let
   *        them log simuntanously.
   */
 class mitkTestLoggingThread : public itk::Object
 {
 public:
 
 mitkClassMacro(mitkTestLoggingThread,itk::Object);
 mitkNewMacro1Param(mitkTestLoggingThread,itk::MultiThreader::Pointer);
 
 int NumberOfMessages;
 
 protected:
 
 mitkTestLoggingThread(itk::MultiThreader::Pointer MultiThreader)
   {
   ThreadID = -1;
   NumberOfMessages = 0;
   m_MultiThreader = MultiThreader;
   }
 
 bool LoggingRunning;
 
 int ThreadID;
 
 itk::MultiThreader::Pointer m_MultiThreader;
 
 void LogMessages()
   {
 
   while(LoggingRunning)
     {
     MITK_INFO << "Test info stream in thread" << ThreadID << "\n even with newlines";
     MITK_WARN << "Test warning stream in thread " << ThreadID <<". "
               << "Even with a very long text, even without meaning or implied meaning or content, just a long sentence to see whether something has problems with long sentences or output in files or into windows or commandlines or whatever.";
     MITK_DEBUG << "Test debugging stream in thread " << ThreadID;
     MITK_ERROR << "Test error stream in thread " << ThreadID;
     MITK_FATAL << "Test fatal stream in thread " << ThreadID;
 
     NumberOfMessages += 5;
     }
   }
 
 
 static ITK_THREAD_RETURN_TYPE ThreadStartTracking(void* pInfoStruct)
   {
   /* extract this pointer from Thread Info structure */
   struct itk::MultiThreader::ThreadInfoStruct * pInfo = (struct itk::MultiThreader::ThreadInfoStruct*)pInfoStruct;
   if (pInfo == NULL)
   {
     return ITK_THREAD_RETURN_VALUE;
   }
   if (pInfo->UserData == NULL)
   {
     return ITK_THREAD_RETURN_VALUE;
   }
   mitkTestLoggingThread *thisthread = (mitkTestLoggingThread*)pInfo->UserData;
 
   if (thisthread != NULL)
     thisthread->LogMessages();
 
   return ITK_THREAD_RETURN_VALUE;
   }
 
 public:
 
 int Start()
   {
   LoggingRunning = true;
   this->ThreadID = m_MultiThreader->SpawnThread(this->ThreadStartTracking, this);
   return ThreadID;
   }
 
 void Stop()
   {
   LoggingRunning = false;
   }
 
 };
 
 /** Documentation
  *
  *  @brief This class holds static test methods to sturcture the test of the mitk logging mechanism.
  */
 class mitkLogTestClass
 {
 
 public:
 
 static void TestSimpleLog()
     {
     bool testSucceded = true;
     try
       {
       MITK_INFO << "Test info stream.";
       MITK_WARN << "Test warning stream.";
       MITK_DEBUG << "Test debugging stream."; //only activated if cmake variable is on!
                                               //so no worries if you see no output for this line
       MITK_ERROR << "Test error stream.";
       MITK_FATAL << "Test fatal stream.";
       }
     catch(mitk::Exception e)
       {
       testSucceded = false;
       }
     MITK_TEST_CONDITION_REQUIRED(testSucceded,"Test logging streams.");
     }
 
 static void TestObjectInfoLogging()
     {
     bool testSucceded = true;
     try
       {
       int i = 123;
       float f = .32234;
       double d = 123123;
       std::string testString = "testString";
       std::stringstream testStringStream;
       testStringStream << "test" << "String" << "Stream";
       mitk::Point3D testMitkPoint;
       testMitkPoint.Fill(2);
 
       MITK_INFO << i;
       MITK_INFO << f;
       MITK_INFO << d;
       MITK_INFO << testString;
       MITK_INFO << testStringStream;
       MITK_INFO << testMitkPoint;
       }
     catch(mitk::Exception e)
       {
       testSucceded = false;
       }
     MITK_TEST_CONDITION_REQUIRED(testSucceded,"Test logging of object information.");
     }
 
 
 
 
 static void TestThreadSaveLog(bool toFile)
     {
     bool testSucceded = true;
 
 
     try
       {
         if (toFile)
         {
           std::string filename = mitk::StandardFileLocations::GetInstance()->GetOptionDirectory() + "/testthreadlog.log";
+          itksys::SystemTools::RemoveFile(filename.c_str()); // remove old file, we do not want to append to large files
           mitk::LoggingBackend::SetLogFile(filename.c_str());
         }
 
         unsigned int numberOfThreads = 20;
         unsigned int threadRuntimeInMilliseconds = 2000;
 
         std::vector<unsigned int> threadIDs;
         std::vector<mitkTestLoggingThread::Pointer> threads;
 
         itk::MultiThreader::Pointer multiThreader = itk::MultiThreader::New();
         for (unsigned int threadIdx = 0; threadIdx < numberOfThreads; ++threadIdx)
         {
           //initialize threads...
           mitkTestLoggingThread::Pointer newThread = mitkTestLoggingThread::New(multiThreader);
           threads.push_back(newThread);
           std::cout << "Created " << threadIdx << ". thread." << std::endl;
         }
 
         for (unsigned int threadIdx = 0; threadIdx < numberOfThreads; ++threadIdx)
         {
           //start them
           std::cout << "Start " << threadIdx << ". thread." << std::endl;
           threadIDs.push_back( threads[threadIdx]->Start() );
           std::cout << threadIdx << ". thread has ID " << threadIDs[threadIdx] << std::endl;
         }
 
         //wait for some time (milliseconds)
         itksys::SystemTools::Delay( threadRuntimeInMilliseconds );
 
 
         for (unsigned int threadIdx = 0; threadIdx < numberOfThreads; ++threadIdx)
         {
           //stop them
           std::cout << "Stop " << threadIdx << ". thread." << std::endl;
           threads[threadIdx]->Stop();
         }
 
         for (unsigned int threadIdx = 0; threadIdx < numberOfThreads; ++threadIdx)
         {
           //Wait for all threads to end
           multiThreader->TerminateThread(threadIDs[threadIdx]);
           std::cout << "Terminated " << threadIdx << ". thread (" << threads[threadIdx]->NumberOfMessages << " messages)." << std::endl;
         }
 
       }
     catch(std::exception e)
       {
         MITK_ERROR << "exception during 'TestThreadSaveLog': "<<e.what();
         testSucceded = false;
       }
     catch(...)
       {
         MITK_ERROR << "unknown exception during 'TestThreadSaveLog'";
         testSucceded = false;
       }
 
     //if no error occured until now, everything is ok
     MITK_TEST_CONDITION_REQUIRED(testSucceded,"Test logging in different threads.");
     }
 
 static void TestLoggingToFile()
     {
     std::string filename = mitk::StandardFileLocations::GetInstance()->GetOptionDirectory() + "/testlog.log";
     mitk::LoggingBackend::SetLogFile(filename.c_str());
     MITK_INFO << "Test logging to default filename: " << mitk::LoggingBackend::GetLogFile();
     MITK_TEST_CONDITION_REQUIRED(itksys::SystemTools::FileExists(filename.c_str()),"Testing if log file exists.");
     //TODO delete log file?
     }
 
 static void TestAddAndRemoveBackends()
     {
     mbilog::BackendCout myBackend = mbilog::BackendCout();
     mbilog::RegisterBackend(&myBackend);
     MITK_INFO << "Test logging";
     mbilog::UnregisterBackend(&myBackend);
 
     //if no error occured until now, everything is ok
     MITK_TEST_CONDITION_REQUIRED(true,"Test add/remove logging backend.");
     }
 
 static void  TestDefaultBackend()
     {
     //not possible now, because we cannot unregister the mitk logging backend in the moment. If such a method is added to mbilog utility one may add this test.
     }
 
 
 };
 
 int mitkLogTest(int /* argc */, char* /*argv*/[])
 {
   // always start with this!
   MITK_TEST_BEGIN("Log")
 
   MITK_TEST_OUTPUT(<<"TESTING ALL LOGGING OUTPUTS, ERROR MESSAGES ARE ALSO TESTED AND NOT MEANING AN ERROR OCCURED!")
 
   mitkLogTestClass::TestSimpleLog();
   mitkLogTestClass::TestObjectInfoLogging();
 
   mitkLogTestClass::TestLoggingToFile();
   mitkLogTestClass::TestAddAndRemoveBackends();
   mitkLogTestClass::TestThreadSaveLog( false ); // false = to console
   mitkLogTestClass::TestThreadSaveLog( true );  // true = to file
   // TODO actually test file somehow?
 
   // always end with this!
   MITK_TEST_END()
 }
diff --git a/Modules/Qmitk/Testing/CMakeLists.txt b/Modules/Qmitk/Testing/CMakeLists.txt
index 34e18cd209..153cd81e2e 100644
--- a/Modules/Qmitk/Testing/CMakeLists.txt
+++ b/Modules/Qmitk/Testing/CMakeLists.txt
@@ -1 +1 @@
-#MITK_CREATE_MODULE_TESTS()
+MITK_CREATE_MODULE_TESTS()
diff --git a/Modules/Qmitk/Testing/QmitkThreadedLogTest.cpp b/Modules/Qmitk/Testing/QmitkThreadedLogTest.cpp
index d222144b57..2ee94934be 100644
--- a/Modules/Qmitk/Testing/QmitkThreadedLogTest.cpp
+++ b/Modules/Qmitk/Testing/QmitkThreadedLogTest.cpp
@@ -1,110 +1,111 @@
 /*===================================================================
 
 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 "mitkCommon.h"
 #include "mitkTestingMacros.h"
 #include <mitkLog.h>
 #include <itksys/SystemTools.hxx>
 #include <mitkStandardFileLocations.h>
 
 #include <string>
 
 #include <QtConcurrentRun>
 
 
 void LogMessages(unsigned int threadID, unsigned int numberOfTimes)
 {
   unsigned int times = 0;
 
   while(times < numberOfTimes)
   {
     MITK_INFO << "Test info stream in thread" << threadID << "\n even with newlines";
     MITK_WARN << "Test warning stream in thread " << threadID <<". "
       << "Even with a very long text, even without meaning or implied meaning or content, just a long sentence to see whether something has problems with long sentences or output in files or into windows or commandlines or whatever.";
     MITK_DEBUG << "Test debugging stream in thread " << threadID;
     MITK_ERROR << "Test error stream in thread " << threadID;
     MITK_FATAL << "Test fatal stream in thread " << threadID;
 
     times += 5;
   }
 }
 
 /**
   \brief Test logging from Qt threads
 */
 static void TestThreadSaveLog(bool toFile)
 {
   bool testSucceded = true;
 
   try
   {
     if (toFile)
     {
       std::string filename = mitk::StandardFileLocations::GetInstance()->GetOptionDirectory() + "/qtestthreadlog.log";
+      itksys::SystemTools::RemoveFile(filename.c_str()); // remove old file, we do not want to append to large files
       mitk::LoggingBackend::SetLogFile(filename.c_str());
     }
 
-    unsigned int numberOfThreads = 20;
+    unsigned int numberOfThreads = 10;
     unsigned int threadRuntimeInMilliseconds = 4000;
     QVector< QFuture<void> > threads;
 
     // Spawn some threads
     for (unsigned int threadIdx = 0; threadIdx < numberOfThreads;++threadIdx)
     {
       threads.push_back( QtConcurrent::run( LogMessages, threadIdx, 100 ) );
       std::cout << "Created " << threadIdx << ". thread." << std::endl;
     }
 
     //wait for some time (milliseconds)
     itksys::SystemTools::Delay( threadRuntimeInMilliseconds );
 
     // Wait for all to finish
     for (unsigned int threadIdx = 0; threadIdx < numberOfThreads;++threadIdx)
     {
       threads[threadIdx].waitForFinished();
       std::cout << threadIdx << ". thread has finished" << std::endl;
     }
   }
   catch(std::exception e)
   {
     MITK_ERROR << "exception during 'TestThreadSaveLog': "<<e.what();
     testSucceded = false;
   }
   catch(...)
   {
     MITK_ERROR << "unknown exception during 'TestThreadSaveLog'";
     testSucceded = false;
   }
 
   //if no error occured until now, everything is ok
   MITK_TEST_CONDITION_REQUIRED(testSucceded,"Test logging in different threads.");
 }
 
 int QmitkThreadedLogTest(int /* argc */, char* /*argv*/[])
 {
   // always start with this!
   MITK_TEST_BEGIN("QmitkThreadedLogTest")
 
   MITK_TEST_OUTPUT(<<"TESTING ALL LOGGING OUTPUTS, ERROR MESSAGES ARE ALSO TESTED AND NOT MEANING AN ERROR OCCURED!")
 
   TestThreadSaveLog( false ); // false = to console
   TestThreadSaveLog( true );  // true = to file
 
   MITK_TEST_OUTPUT(<<"Number of threads in QThreadPool: " << QThreadPool::globalInstance()->maxThreadCount() )
 
   // always end with this!
   MITK_TEST_END()
 }
diff --git a/Modules/Qmitk/Testing/files.cmake b/Modules/Qmitk/Testing/files.cmake
index 73e86e3374..fde1671c1e 100644
--- a/Modules/Qmitk/Testing/files.cmake
+++ b/Modules/Qmitk/Testing/files.cmake
@@ -1,3 +1,8 @@
-set(MODULE_TESTS
-  QmitkThreadedLogTest.cpp
-)
+# test fails on MacOS, needs to be fixed before permanent activation (bug 15479)
+if (NOT CMAKE_HOST_APPLE)
+
+  set(MODULE_TESTS
+    QmitkThreadedLogTest.cpp
+  )
+
+endif()
\ No newline at end of file