option with C-G solver doesn't work

[JingtianKang]

Hi friends,
The C-G solver doesn't work. For instance, I modify the input file "Abaqus_uel_holeplate_3d.in" :

     %SOLVER, DIRECT, LINEAR
     SOLVER, CONJUGATE GRADIENT, LINEAR

The program will stop with bug reporting at the subroutine:
"subroutine assemble_projection_mass_matrix"

Thanks

Jingtian