Android Build Failed Unknown Error

Your error from your log:

"ERROR: C:/Program Files (x86)/Android/android-ndk-r10d/ndk-build.cmd failed with args APP_ABI=“armeabi-v7a " NDK_DEBUG=1”

I have the same error, but on mac – 47-os-x-android-packaging-ndk-fails

On Windows, possibly you can try to run engine as administrator, like here – android-packaging-error-ndk-buildcmd