Ipython: IPython 노트북 오류: 노트북을 로드하는 동안 오류가 발생했습니다.

지난 몇 분 동안 이전에 Python3.4로 만든 .ipynb 파일에 액세스할 수 없었습니다. 이 파일이 있는 하위 디렉토리로 이동하여 다음을 입력합니다.

ipython3 notebook

특정 .ipynb 파일을 클릭하면 다음 오류가 발생합니다.

An unknown error occurred while loading this notebook. This version can load notebook formats v4 or earlier. See the server log for details.

[E 00:19:41.468 NotebookApp] Unhandled error in API request
    Traceback (most recent call last):
      File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/traitlets/traitlets.py", line 460, in get
        value = obj._trait_values[self.name]
    KeyError: 'db'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/notebook/base/handlers.py", line 458, in wrapper
    result = yield gen.maybe_future(method(self, *args, **kwargs))
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/tornado/gen.py", line 1008, in run
    value = future.result()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/tornado/concurrent.py", line 232, in result
    raise_exc_info(self._exc_info)
  File "<string>", line 3, in raise_exc_info
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/tornado/gen.py", line 282, in wrapper
    yielded = next(result)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/notebook/services/contents/handlers.py", line 124, in get
    path=path, type=type, format=format, content=content,
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/notebook/services/contents/filemanager.py", line 354, in get
    model = self._notebook_model(path, content=content)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/notebook/services/contents/filemanager.py", line 314, in _notebook_model
    self.mark_trusted_cells(nb, path)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/notebook/services/contents/manager.py", line 447, in mark_trusted_cells
    trusted = self.notary.check_signature(nb)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/nbformat/sign.py", line 220, in check_signature
    if self.db is None:
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/traitlets/traitlets.py", line 488, in __get__
    return self.get(obj, cls)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/traitlets/traitlets.py", line 467, in get
    value = self._validate(obj, dynamic_default())
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/nbformat/sign.py", line 127, in _db_default
    self.init_db(db)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/nbformat/sign.py", line 139, in init_db
    )""")
sqlite3.DatabaseError: database disk image is malformed

이 문제를 어떻게 해결합니까?