diff --git a/Modules/IGTBase/autoload/IO/mitkNavigationDataReaderCSV.cpp b/Modules/IGTBase/autoload/IO/mitkNavigationDataReaderCSV.cpp
index 7f7caba6a3..c3983e5120 100644
--- a/Modules/IGTBase/autoload/IO/mitkNavigationDataReaderCSV.cpp
+++ b/Modules/IGTBase/autoload/IO/mitkNavigationDataReaderCSV.cpp
@@ -1,180 +1,180 @@
 /*===================================================================
 
 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.
 
 ===================================================================*/
 
 // MITK
 #include "mitkNavigationDataReaderCSV.h"
 #include <mitkIGTMimeTypes.h>
 
 // STL
 #include <fstream>
 
 
 mitk::NavigationDataReaderCSV::NavigationDataReaderCSV() : AbstractFileReader(
   mitk::IGTMimeTypes::NAVIGATIONDATASETCSV_MIMETYPE(),
   "MITK NavigationData Reader (CSV)")
 {
   RegisterService();
 }
 
 mitk::NavigationDataReaderCSV::NavigationDataReaderCSV(const mitk::NavigationDataReaderCSV& other) : AbstractFileReader(other)
 {
 }
 
 mitk::NavigationDataReaderCSV::~NavigationDataReaderCSV()
 {
 }
 
 mitk::NavigationDataReaderCSV* mitk::NavigationDataReaderCSV::Clone() const
 {
   return new NavigationDataReaderCSV(*this);
 }
 
 std::vector<itk::SmartPointer<mitk::BaseData>> mitk::NavigationDataReaderCSV::Read()
 {
   std::vector<std::string> fileContent = GetFileContentLineByLine(GetInputLocation());
   int NumOfTools = getNumberOfToolsInLine(fileContent[0]);
 
   mitk::NavigationDataSet::Pointer returnValue = mitk::NavigationDataSet::New(NumOfTools);
   std::vector<mitk::BaseData::Pointer> result;
   result.push_back(returnValue.GetPointer());
 
   // start from line 1 to leave out header
-  for (int i = 1; i<fileContent.size(); i++)
+  for (unsigned int i = 1; i<fileContent.size(); i++)
   {
     returnValue->AddNavigationDatas(parseLine(fileContent[i], NumOfTools));
   }
 
   return result;
 }
 
 
 int mitk::NavigationDataReaderCSV::getNumberOfToolsInLine(std::string line)
 {
   std::vector<std::string> tokens=splitLine(line);
  int size = tokens.size();
  int NumOfTools = (size-1)/8;
 
  if ( (size-1)%8 != 0 )
  {
    MITK_ERROR("mitkNavigationDataReader") << "Illegal csv-file! Unexpected number of columns found! Assuming " << NumOfTools << " tools!";
  }
 
  return NumOfTools ;
 }
 
 std::vector<std::string> mitk::NavigationDataReaderCSV::splitLine(std::string line)
 {
    std::vector<std::string> elems;
    std::stringstream ss(line);
    std::string item;
    while (std::getline(ss, item, ';')) {
      elems.push_back(item);
    }
    return elems;
 }
 
 mitk::NavigationData::Pointer mitk::NavigationDataReaderCSV::CreateNd(std::string timestamp, std::string valid, std::string X, std::string Y, std::string Z, std::string QX, std::string QY, std::string QZ, std::string QR)
 {
   mitk::NavigationData::Pointer result= mitk::NavigationData::New();
 
   mitk::Point3D position;
   mitk::Quaternion orientation;
   bool isValid = false;
   double time;
 
   time = StringToDouble(timestamp);
 
   if (valid == "1") isValid = true;
   else isValid = false;
 
   position[0] = StringToDouble(X);
   position[1] = StringToDouble(Y);
   position[2] = StringToDouble(Z);
 
   orientation[0] = StringToDouble(QX);
   orientation[1] = StringToDouble(QY);
   orientation[2] = StringToDouble(QZ);
   orientation[3] = StringToDouble(QR);
 
   result->SetIGTTimeStamp(time);
   result->SetDataValid(isValid);
   result->SetPosition(position);
   result->SetOrientation(orientation);
   return result;
 }
 
 double mitk::NavigationDataReaderCSV::StringToDouble( const std::string& s )
 {
   std::istringstream i(s);
   double x;
     if (!(i >> x))
       return 0;
     return x;
 }
 
 std::vector<mitk::NavigationData::Pointer> mitk::NavigationDataReaderCSV::parseLine(std::string line, int NumOfTools)
 {
   std::vector<std::string> parts = splitLine(line);
   std::vector<mitk::NavigationData::Pointer> result;
 
 
 
   for (int n = 0; n < NumOfTools; n++)
   {
     mitk::NavigationData::Pointer nd;
     int offset = n * 8;
     nd = CreateNd(parts[0], parts[offset + 1], parts[offset + 2], parts[offset + 3], parts[offset + 4], parts[offset + 5], parts[offset + 6], parts[offset + 7], parts[offset + 8]);
     result.push_back(nd);
   }
   return result;
 }
 
 
 std::vector<std::string> mitk::NavigationDataReaderCSV::GetFileContentLineByLine(std::string filename)
 {
 std::vector<std::string> readData = std::vector<std::string>();
 
 //save old locale
 char * oldLocale;
 oldLocale = setlocale( LC_ALL, nullptr );
 
 //define own locale
 std::locale C("C");
 setlocale( LC_ALL, "C" );
 
 //read file
 std::ifstream file;
 file.open(filename.c_str(), std::ios::in);
 if (file.good())
     {
     //read out file
     file.seekg(0L, std::ios::beg);  // move to begin of file
     while (! file.eof())
       {
       std::string buffer;
       std::getline(file,buffer);    // read out file line by line
       if (buffer.size() > 0) readData.push_back(buffer);
 
       }
     }
 
 file.close();
 
 //switch back to old locale
 setlocale( LC_ALL, oldLocale );
 
 return readData;
 }