dft energy gradients error in qm/mm dft dynamics

   I am trying to run a qmmm dft dynamics and it is finished. But when I checked the .out file I found “**********” about  dft energy gradients.

======================== echo of input deck ========================

 start Li4W

 memory 5000 mb

 permanent_dir /tmp/perm

 scratch_dir /tmp/data

 print medium

 ECHO

 charge 1

 prepare

 source Li4W.pdb

 new_top new_seq

 new_rst

 modify segment 1  quantum

 modify segment 2  quantum

 modify segment 3  quantum

 modify segment 4  quantum

 modify segment 5  quantum

 center

 orient

 solvate box 3.0

 update lists

 ignore

 write Li4W_qmmm.pdb

 write Li4W_qmmm.rst

 end

 task prepare

 md

  system Li4W_qmmm

  step 0.001 equil 20000 data 10000

  cutoff 0.9

  mwm 3000

  isotherm

  isobar

  print step 10 stat 100

  print step 10 stat 100

  update pairs 10

  record rest 100

  record prop 100 sync 10 times 0

  record coord 100

  profile

  load pairs 10 size 0.75

  test 10

 end

 basis

  Li library "6-31G"

  O library "6-31G"

  H library "6-31G"

  end

  dft

  xc b3lyp

  mult 1

  direct

  iterations 600

  print medium

 end

 qmmm

  region    qm solvent

  maxiter   25    3000

  ncycles   50

  density   espfit

  xyz foo

  link_atoms hydrogen

 end

 task qmmm dft energy

 task qmmm dft optimize

 task qmmm dft dynamics

                           NWChem DFT Gradient Module

                           --------------------------

 charge          =   1.00

 wavefunction    = closed shell

                        DFT ENERGY GRADIENTS

   atom               coordinates                        gradient

                x          y          z           x          y          z

  1 Li     -4.475640  -8.284437   5.230146    0.020383  -0.008359  -0.000110

  2 O      -3.967871  -1.228513  -8.847790   -0.006356   0.001474   0.000454

  3 H     ********** **********  18.456001    0.000000   0.000000   0.000000

  4 H     110.878117 653.045873 **********    0.000000   0.000000   0.000000

  5 O      -0.955485  63.404394  41.959452   -0.054171  -0.046236  -0.046649

  6 H     ********** ********** **********    0.000000   0.000000   0.000000

  7 H       1.158792  65.209798  43.780103    0.054168   0.046242   0.046656

  8 O       1.853687  -3.822455 -15.868814    0.065222   0.017756  -0.049402

  9 H       1.601139  -3.325501 -13.972917   -0.027496   0.003151   0.065014

 10 H       3.173129  -3.358243 -16.976428   -0.042934  -0.020353  -0.001204

 11 O      -2.486859  -1.646881 -19.571390   -0.018765   0.019700  -0.019822

 12 H      -1.113905  -2.940998 -18.930303    0.032108  -0.049201   0.003566

 13 H      -2.368873   0.061577 -18.651385   -0.003497   0.033988   0.031490

                ----------------------------------------

                |  Time  |  1-e(secs)   |  2-e(secs)   |

                ----------------------------------------

                |  CPU   |       0.04   |       0.03   |

                ----------------------------------------

                |  WALL  |       0.05   |       0.03   |

                ----------------------------------------

Bq nuclear interaction energy =  0.121898254914254

Total number of active Bq charges                     0

frozen_density,esp T T

disabling frozen_density,esp due to active qm atoms

qmmm_main                       failed qmmm_energy_gradient        0

qmmm_main                       failed qmmm_energy_gradient        0

For further details see manual section: No section for this category                                                                                                              

Could someone give me some suggestions? Each advice will be highly appreciated.