Rama z-score failed  failed.

/net/marbles/raid1/dorothee/rerefine/cryoem/data_no_H/6pom_20416/07_2024/6pom_20416.cif /net/marbles/raid1/dorothee/rerefine/cryoem/data_no_H/6pom_20416/07_2024/6pom_20416.map 4.9
Traceback (most recent call last):
  File "/net/marbles/raid1/dorothee/rerefine/cryoem/rerefine_script.py", line 420, in get_statistics
    self.json_data[p+'z_score'] = z_scores['W'][0]
TypeError: 'NoneType' object has no attribute '__getitem__'