i'm trying to add polar only hydrogen in Resveratrol ligand, but i'm getting a error.

Traceback (most recent call last):

File "C:\Program Files (x86)\MGLTools-1.5.6\lib\site-packages\ViewerFramework\VF.py", line 898, in tryto

result = command( *args, **kw )

File "C:\Program Files (x86)\MGLTools-1.5.6\lib\site-packages\Pmv\editCommands.py", line 1043, in doit

hat = addh.addHydrogens(mol.allAtoms, method=method)

File "C:\Program Files (x86)\MGLTools-1.5.6\lib\site-packages\PyBabel\addh.py", line 92, in addHydrogens

Hatoms = self.place_hydrogens1(atoms, num_H_to_add)

File "C:\Program Files (x86)\MGLTools-1.5.6\lib\site-packages\PyBabel\addh.py", line 115, in place_hydrogens1

Hat = Hat + self.add_tertiary_hydrogen(a, SP3_C_H_DIST)

File "C:\Program Files (x86)\MGLTools-1.5.6\lib\site-packages\PyBabel\addh.py", line 345, in add_tertiary_hydrogen

s = [ m[0][0] + m[0][1] + m[0][2],

TypeError: 'NoneType' object is unsubscriptable

Anyone know how can i solve this problem ? thanks for your help !