anchor.diff:           ! ED inputs on blade from AeroDyn
         IF (p_FAST%CompElast == Module_ED) THEN
            
  -            ! blades:
  -         AD_Start_Bl = y_FAST%Lin%Modules(MODULE_AD)%Instance(1)%LinStartIndx(LIN_INPUT_COL) &
  -                     + u_AD%TowerMotion%NNodes * 9  & ! 3 fields (MASKID_TRANSLATIONDISP,MASKID_Orientation,MASKID_TRANSLATIONVel) with 3 components
  -                     + u_AD%HubMotion%NNodes   * 9    ! 3 fields (MASKID_TRANSLATIONDISP,MASKID_Orientation,MASKID_RotationVel) with 3 components
  -   
  -         do k = 1,size(u_AD%BladeRootMotion)         
  -            AD_Start_Bl = AD_Start_Bl + u_AD%BladeRootMotion(k)%NNodes * 3 ! 1 field (MASKID_Orientation) with 3 components
  -         end do
  -         ! next is u_AD%BladeMotion(k); note that it has 3 fields and we only need 1
  -      
            ED_Start_mt = y_FAST%Lin%Modules(MODULE_ED)%Instance(1)%LinStartIndx(LIN_INPUT_COL)
  +         
            DO K = 1,SIZE(u_ED%BladePtLoads,1) ! Loop through all blades (p_ED%NumBl)
               ED_Start_mt = ED_Start_mt + u_ED%BladePtLoads(k)%NNodes*3 ! skip the forces on this blade
  +            AD_Start_Bl = Indx_u_AD_Blade_Start(u_AD, y_FAST, k) 
               
               CALL Linearize_Line2_to_Point( y_AD%BladeLoad(k), u_ED%BladePtLoads(k), MeshMapData%AD_L_2_BDED_B(k), ErrStat2, ErrMsg2, u_AD%BladeMotion(k), y_ED%BladeLn2Mesh(k) )
                  CALL SetErrStat(ErrStat2, ErrMsg2, ErrStat, ErrMsg, RoutineName)
  
positive.code:    !..........
     
     IF ( p_FAST%CompElast == Module_BD ) THEN ! see routine U_ED_SD_HD_BD_Orca_Residual() in SolveOption1
  
           ED_Start_mt = y_FAST%Lin%Modules(MODULE_ED)%Instance(1)%LinStartIndx(LIN_INPUT_COL)
           ! u_ED%BladePtLoads(i)%NNodes = 0 here
           ED_Start_mt = ED_Start_mt + u_ED%PlatformPtMesh%NNodes * 6      &      ! 3 forces + 3 moments at each node
                                     + u_ED%TowerPtLoads%NNodes   * 6      &      ! 3 forces + 3 moments at each node
                                     + u_ED%HubPtLoad%NNodes      * 3             ! 3 forces at the hub (so we start at the moments)
     
           ! Transfer BD loads to ED hub input:
           ! we're mapping loads, so we also need the sibling meshes' displacements:
  
negative.code:    end if
        
  END SUBROUTINE Linear_ED_InputSolve_du
  
  
  !----------------------------------------------------------------------------------------------------------------------------------
  !> This routine forms the dU^{BD}/du^{BD} and dU^{BD}/du^{AD} blocks (BD row) of dUdu. (i.e., how do changes in the AD and BD inputs 
  