error: 'Vector' is not a member of 'Eigen'

I'm using an old code that use Eigen library, and the code contain these declaration Eigen::Vector<num_t, 3> v = V.row(i).transpose(); i currently using the last version of eigen 3.3.7, and i trying to compile my file but i'm failed and got this error Eigen::Vector<num_t, 3> v. what i can do to fix it?