Rama z-score failed  failed.

/net/cci-nas-00/data/ceres_data/8hd6_34670/02_2025/8hd6_34670.cif /net/cci-nas-00/data/ceres_data/8hd6_34670/02_2025/8hd6_34670.map 3.73
Traceback (most recent call last):
  File "/net/marbles/raid1/dorothee/rerefine/cryoem/rerefine_script.py", line 421, in get_statistics
    self.json_data[p+'z_score'] = z_scores['W'][0]
TypeError: 'NoneType' object has no attribute '__getitem__'