CMake error with OpenCV 3.2/contrib on .dnn directory

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I am using CMake 3.8.1 and downloaded OpenCV 3.2 and opencv_contrib_master at the same time from Github.

I specified the opencv_contrib_master directory in the OPENCV_EXTRA_MODULES_PATH line. I also deselected at least protobuf and BUILD_opencv_dnn.

However, when I try and configure in CMake I get an error saying:

CMake Error at cmake/OpenCVModule.cmake:294 (add_subdirectory):
  The binary directory

C:/OpenCV/build/modules/dnn/.dnn

  is already used to build a source directory.  It cannot be used to build
  source directory

D:/opencv_contrib-master/modules/dnn

  Specify a unique binary directory name.
Call Stack (most recent call first):
  modules/CMakeLists.txt:7 (ocv_glob_modules)

I completely deleted the opencv and the contrib directories and downloaded the packages from GitHub within 2 minutes. I deselected aruco and bioinspired. I specified the proper contrib directory for the AXTRA_MODULES_PATH. Now I get:

CMake Error at D:/opencv/cmake/OpenCVUtils.cmake:850 (file):
  file MD5 failed to read file "C:/OpenCV/build/3rdparty/tinydnn/":
  Permission denied
Call Stack (most recent call first):
   C:/opencv_contrib-master/modules/dnn_modern/CMakeLists.txt:20 (ocv_download)

Downloading ...
CMake Error at D:/opencv/cmake/OpenCVUtils.cmake:888 (file):
  file DOWNLOAD cannot open file for write.
Call Stack (most recent call first):
  C:/opencv_contrib-master/modules/dnn_modern/CMakeLists.txt:20 (ocv_download)


CMake Error at D:/opencv/cmake/OpenCVUtils.cmake:892 (message):
  Failed to download .  Status=
Call Stack (most recent call first):
   C:/opencv_contrib-master/modules/dnn_modern/CMakeLists.txt:20 (ocv_download)

Any help appreciated.