"error C3646: 'CV_OVERRIDE': unknown override specifier" when building with opencv_contrib

edit

Hi I'm trying to use the face.hpp in the opencv_contrib library. My build fails because of the error stated "\opencv_contrib2\install\include\opencv2\face.hpp(336): error C3646: 'CV_OVERRIDE': unknown override specifier", a whole bunch of them with changing number in brackets. I'm not sure what this error means or how I can fix it. If you could shed some light on the meaning of this error or possible solutions I would very much appreciate that.