fix crash related to not support the z length modifier for size_t on vs
Merge pull request #4887 from Dhilan007/develop_crash

fix crash related to not support the z length modifier for size_t on vs
fixed #3482
		1.   add override to  virtual functions.
                 2.   replace std::string::npos  to filePath.npos.
                 3.   replace std::string to  const std::string& .
Merge branch 'develop' into #3582