Error in cmake_gui while configuring the contrib modules

edit

I am using Cmake-gui 3.8.1 version (also tried 3.9 & 3.12) and Visual Studio 2017. I am getting the follwing error after pressing 'Configure' button.

CMake Warning at cmake/OpenCVDownload.cmake:193 (message):
  FFMPEG: Download failed: 5;"Couldn't resolve proxy name"

  For details please refer to the download log file:

  C:/OpenCV/CMakeDownloadLog.txt

Call Stack (most recent call first):
  3rdparty/ffmpeg/ffmpeg.cmake:20 (ocv_download)
  cmake/OpenCVFindLibsVideo.cmake:228 (download_win_ffmpeg)
  CMakeLists.txt:634 (include)


FFMPEG: Download: opencv_ffmpeg_64.dll
CMake Warning at cmake/OpenCVDownload.cmake:193 (message):
  FFMPEG: Download failed: 5;"Couldn't resolve proxy name"

  For details please refer to the download log file:

  C:/OpenCV/CMakeDownloadLog.txt

Call Stack (most recent call first):
  3rdparty/ffmpeg/ffmpeg.cmake:20 (ocv_download)
  cmake/OpenCVFindLibsVideo.cmake:228 (download_win_ffmpeg)
  CMakeLists.txt:634 (include)


FFMPEG: Download: ffmpeg_version.cmake
CMake Warning at cmake/OpenCVDownload.cmake:193 (message):
  FFMPEG: Download failed: 5;"Couldn't resolve proxy name"

  For details please refer to the download log file:

  C:/OpenCV/CMakeDownloadLog.txt

Call Stack (most recent call first):
  3rdparty/ffmpeg/ffmpeg.cmake:20 (ocv_download)
  cmake/OpenCVFindLibsVideo.cmake:228 (download_win_ffmpeg)
  CMakeLists.txt:634 (include)

IPPICV: Download: ippicv_2017u3_win_intel64_general_20180518.zip
CMake Warning at cmake/OpenCVDownload.cmake:193 (message):
  IPPICV: Download failed: 5;"Couldn't resolve proxy name"

  For details please refer to the download log file:

  C:/OpenCV/CMakeDownloadLog.txt

Call Stack (most recent call first):
  3rdparty/ippicv/ippicv.cmake:42 (ocv_download)
  cmake/OpenCVFindIPP.cmake:243 (download_ippicv)
  cmake/OpenCVFindLibsPerf.cmake:19 (include)
  CMakeLists.txt:635 (include)

I am pasting the 'C:/OpenCV/CMakeDownloadLog.txt' file below:

#use_cache "C:/Downloads/OPENCV/opencv-master/.cache"
#do_copy "opencv_ffmpeg.dll" "b8120c07962d591e2e9071a1bf566fd0" "https://raw.githubusercontent.com/opencv/opencv_3rdparty/0a0e88972a7ea97708378d0488a65f83e7cc5e69/ffmpeg/opencv_ffmpeg.dll" "C:/OpenCV/3rdparty/ffmpeg"
#missing "C:/OpenCV/3rdparty/ffmpeg/opencv_ffmpeg.dll"
#cmake_download "C:/Downloads/OPENCV/opencv-master/.cache/ffmpeg/b8120c07962d591e2e9071a1bf566fd0-opencv_ffmpeg.dll" "https://raw.githubusercontent.com/opencv/opencv_3rdparty/0a0e88972a7ea97708378d0488a65f83e7cc5e69/ffmpeg/opencv_ffmpeg.dll"
# timeout on name lookup is not supported
# Curl_ipv4_resolve_r failed for proxy name
# Couldn't resolve proxy 'proxy name'
# Closing connection 0
# 

#do_copy "opencv_ffmpeg_64.dll" "dc9c50e7b05482acc25d6ce0ac61bf1d" "https://raw.githubusercontent.com/opencv/opencv_3rdparty/0a0e88972a7ea97708378d0488a65f83e7cc5e69/ffmpeg/opencv_ffmpeg_64.dll" "C:/OpenCV/3rdparty/ffmpeg"
#missing "C:/OpenCV/3rdparty/ffmpeg/opencv_ffmpeg_64.dll"
#cmake_download "C:/Downloads/OPENCV/opencv-master/.cache/ffmpeg/dc9c50e7b05482acc25d6ce0ac61bf1d-opencv_ffmpeg_64.dll" "https://raw.githubusercontent.com/opencv/opencv_3rdparty/0a0e88972a7ea97708378d0488a65f83e7cc5e69/ffmpeg/opencv_ffmpeg_64.dll"
# timeout on name lookup is not supported
# Curl_ipv4_resolve_r failed for proxy name
# Couldn't resolve proxy 'proxy name'
# Closing connection 0
# 

#do_copy "ffmpeg_version.cmake" "3b90f67f4b429e77d3da36698cef700c" "https://raw.githubusercontent.com/opencv/opencv_3rdparty/0a0e88972a7ea97708378d0488a65f83e7cc5e69/ffmpeg/ffmpeg_version.cmake" "C:/OpenCV/3rdparty/ffmpeg"
#missing "C:/OpenCV/3rdparty/ffmpeg/ffmpeg_version.cmake"
#cmake_download "C:/Downloads/OPENCV/opencv-master/.cache/ffmpeg/3b90f67f4b429e77d3da36698cef700c-ffmpeg_version.cmake" "https://raw.githubusercontent.com/opencv/opencv_3rdparty/0a0e88972a7ea97708378d0488a65f83e7cc5e69/ffmpeg/ffmpeg_version.cmake"
# timeout on name lookup is not supported
# Curl_ipv4_resolve_r failed for proxy name
# Couldn't resolve proxy 'proxy name'
# Closing connection 0
# 

#do_unpack "ippicv_2017u3_win_intel64_general_20180518.zip" "915ff92958089ede8ea532d3c4fe7187" "https://raw.githubusercontent.com/opencv/opencv_3rdparty/bdb7bb85f34a8cb0d35e40a81f58da431aa1557a/ippicv/ippicv_2017u3_win_intel64_general_20180518.zip" "C:/OpenCV/3rdparty/ippicv"
#cmake_download "C:/Downloads/OPENCV/opencv-master/.cache/ippicv/915ff92958089ede8ea532d3c4fe7187-ippicv_2017u3_win_intel64_general_20180518.zip" "https://raw.githubusercontent.com/opencv/opencv_3rdparty/bdb7bb85f34a8cb0d35e40a81f58da431aa1557a/ippicv/ippicv_2017u3_win_intel64_general_20180518.zip"
# timeout on ...