When Running PyMOL from a python script I get the error message
"unable to import fragment XXX", where XXX is 'ala', 'cys', 'acetylene' etc.

I get this message when I try to use the mutagenesis wizard or any other function that need access to the fragment library, like adding a alanine residue with "ALT+A"

The header of my script is

import pymol
from pymol import cmd, stored

I try importing everything from pymol using

from pymol import *

but I get the same error.

Thanks in advance.