Error in configuration process,projects files may be invalid error when building Opencv 3.1.0 and Opencv_Extra_module for Android from source?

Question

I am building Opencv 3.1.0 and Opencv_Extra_module for Android from source using the following procedures using CMake and mingw

1. start cmake-gui and select the opencv source code folder and the folder where binaries will be built (the 2 upper forms of the interface)

2. Press the Add Entry button and set Name=ANDROID_NDK select path and add the ndk directory to value

3. press the configure button. I choose the Specify toolchain for cross-compiling. Press Next and specify the toolchain file and i set to C:/Users/The/Documents/opencv-master/platforms/android/android.toolchain.cmake. Press finish it builds fine but there are two many reptitive warning

   i) CMake Deprecation Warning at C:/CMake/share/cmake 3.7/ Modules/CMakeForce Compiler.cmake:69 (message):The CMAKE_FORCE_C_COMPILER macro is deprecated. Instead just set CMAKE_C_COMPILER and allow CMake to identify the compiler.

   ii) CMake Deprecation Warning at C:/CMake/share/cmake-3.7/Modules/ CMakeForce Compiler.cmake:83 (message):The CMAKE_FORCE_CXX_COMPILER macro is deprecated. Instead just set CMAKE_CXX_COMPILER and allow CMake to identify the compiler.

4. To compile the Opencv Extra module set the OPENCV_EXTRA_MODULES_PATH=C:\Users\The\Downloads\opencv_contrib-master\modules

5. press the configure button for the second time but here is the error occuring Error in configuration process,projects files may be invalid error occured on this stage.

   Please help me guys I have been searching for two days on how to build opencv and its extra module for android i asked this question no one answered it?