After a search, I found that latest main version of OpenFAST might be unable to output platform Fx/Fy/Fz/Mx/My/Mz. If so, I have to output Fairlead force when doing linearization. However, the results is the force on each mooring line. In order to get the mooring stiffness matrix, I have to manually add up all results with regards to force and platform DOF. It is inconvenient. Could anyone share me an convenient way to get the mooring stiffness matrix?