run demo error

Hi when i try to follow the instruction to install R-FCN ,i encounter this problem:

Invalid MEX-file '/home/siahooar/Downloads/r-fcn/external/caffe/matlab/+caffe/private/caffe_.mexa64':
/home/siahooar/Downloads/r-fcn/external/caffe/matlab/+caffe/private/caffe_.mexa64: undefined symbol:
_ZN2cv8imencodeERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKNS_11_InputArrayERSt6vectorIhSaIhEERKSB_IiSaIiEE

can anyone give me some advise? Thx~