Opencv_contrib编译错误file DOWNLOAD cannot open file for write.

编译opencv 3.2 + opencv_contrib + vs14的过程中，遇到了以下错误提示：

CMake Error at E:/360Downloads/opencv/sources/cmake/OpenCVUtils.cmake:1043 (file):
  file DOWNLOAD cannot open file for write.
Call Stack (most recent call first):
  E:/360Downloads/opencv_contrib-master/modules/dnn/cmake/OpenCVFindLibProtobuf.cmake:32 (ocv_download)
  E:/360Downloads/opencv_contrib-master/modules/dnn/CMakeLists.txt:5 (include)

CMake Error at E:/360Downloads/opencv/sources/cmake/OpenCVUtils.cmake:1047 (message):
  Failed to download .  Status=
Call Stack (most recent call first):
  E:/360Downloads/opencv_contrib-master/modules/dnn/cmake/OpenCVFindLibProtobuf.cmake:32 (ocv_download)
  E:/360Downloads/opencv_contrib-master/modules/dnn/CMakeLists.txt:5 (include)

编译方法一直按照CSDN其他文章分享的编译步骤，且按照教程下载了相关的文件。

查找错误原因，发现是因为opencv与opencv_contrib的版本不一致导致。

https://github.com/opencv/opencv_contrib/releases

在这个网站下载对应opencv版本的opencv_contrib，问题顺利解决。