CMake error for OpenCV Building in Windows - opencv

Question

https://www.youtube.com/watch?v=9xFTXSDw_9U
I used Python version 3.7
CMake most recent
OpenCV version 4.1.0
OpenCV_contrib 4.1.0
I built OpenCV by referring to the video on the link, but experienced the following error:
CMake Warning at cmake/OpenCVDownload.cmake:193 (message):
IPPICV: Download failed: 22;"HTTP response code said error"
For details please refer to the download log file:
C:/opencv/build/CMakeDownloadLog.txt
Call Stack (most recent call first):
3rdparty/ippicv/ippicv.cmake:42 (ocv_download)
cmake/OpenCVFindIPP.cmake:243 (download_ippicv)
cmake/OpenCVFindLibsPerf.cmake:12 (include)
CMakeLists.txt:773 (include)
CMake Warning at cmake/OpenCVDownload.cmake:193 (message):
ADE: Download failed: 22;"HTTP response code said error"
For details please refer to the download log file:
C:/opencv/build/CMakeDownloadLog.txt
Call Stack (most recent call first):
modules/gapi/cmake/DownloadADE.cmake:10 (ocv_download)
modules/gapi/cmake/init.cmake:16 (include)
cmake/OpenCVModule.cmake:312 (include)
cmake/OpenCVModule.cmake:375 (_add_modules_1)
modules/CMakeLists.txt:7 (ocv_glob_modules)
For details please refer to the download log file:
C:/opencv/build/CMakeDownloadLog.txt
Call Stack (most recent call first):
3rdparty/ffmpeg/ffmpeg.cmake:20 (ocv_download)
modules/videoio/cmake/detect_ffmpeg.cmake:14 (download_win_ffmpeg)
modules/videoio/cmake/init.cmake:3 (include)
modules/videoio/cmake/init.cmake:24 (add_backend)
cmake/OpenCVModule.cmake:312 (include)
cmake/OpenCVModule.cmake:375 (_add_modules_1)
modules/CMakeLists.txt:7 (ocv_glob_modules)
CMake Warning at cmake/OpenCVDownload.cmake:193 (message):
FFMPEG: Download failed: 22;"HTTP response code said error"
For details please refer to the download log file:
C:/opencv/build/CMakeDownloadLog.txt
Call Stack (most recent call first):
3rdparty/ffmpeg/ffmpeg.cmake:20 (ocv_download)
modules/videoio/cmake/detect_ffmpeg.cmake:14 (download_win_ffmpeg)
modules/videoio/cmake/init.cmake:3 (include)
modules/videoio/cmake/init.cmake:24 (add_backend)
cmake/OpenCVModule.cmake:312 (include)
cmake/OpenCVModule.cmake:375 (_add_modules_1)
modules/CMakeLists.txt:7 (ocv_glob_modules)
Please help me.

Answer 1

According to the logs some downloads are failing: HTTP response code said error
The setup tries to e.g. download IPPICV from https://raw.githubusercontent.com/opencv/opencv_3rdparty/${IPPICV_COMMIT}/ippicv/, given the fact that at the time of writing this answer, GitHub is experiencing an outage, this issue might disappear as soon as GitHub is operational again (https://www.githubstatus.com/)