Rama z-score failed  failed.

/net/cci-nas-00/data/ceres_data/7yci_33740/02_2025/7yci_33740.cif /net/cci-nas-00/data/ceres_data/7yci_33740/02_2025/7yci_33740.map 2.98
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__'