KeepNote/Linux Mint 17.1 stopped opening Notebooks in the Documents folder, how do I correct this

[MR2015]

Hello,

I have several notebooks in my Documents folder and for some reason last week KeepNote started throwing error: Could not load notebook '/home/<username>/Documents'.

I tried purge and deleting the .config folder, but Notebook still won't access the Document folder. Here's the error log:

==============================================
KeepNote 0.7.8: Sat Jun 13 09:47:05 2015
enabling extension 'keepnote'
enabling extension 'backup_tar'
enabling extension 'new_file'
enabling extension 'editor_insert_date'
enabling extension 'command_basics'
enabling extension 'export_html'
enabling extension 'python_prompt'
enabling extension 'notebook_http'

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/keepnote/gui/__init__.py", line 568, in func
    notebook.load(filename, conn)
  File "/usr/lib/python2.7/dist-packages/keepnote/notebook/__init__.py", line 1403, in load
    self._init_index()
  File "/usr/lib/python2.7/dist-packages/keepnote/notebook/__init__.py", line 1467, in _init_index
    self._conn.index_attr("icon", "TEXT")
  File "/usr/lib/python2.7/dist-packages/keepnote/notebook/connection/fs/__init__.py", line 1349, in index_attr
    self._index.add_attr(notebook_index.AttrIndex(key, index_type,
AttributeError: 'NoneType' object has no attribute 'add_attr'

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/keepnote/gui/__init__.py", line 568, in func
    notebook.load(filename, conn)
  File "/usr/lib/python2.7/dist-packages/keepnote/notebook/__init__.py", line 1403, in load
    self._init_index()
  File "/usr/lib/python2.7/dist-packages/keepnote/notebook/__init__.py", line 1467, in _init_index
    self._conn.index_attr("icon", "TEXT")
  File "/usr/lib/python2.7/dist-packages/keepnote/notebook/connection/fs/__init__.py", line 1349, in index_attr
    self._index.add_attr(notebook_index.AttrIndex(key, index_type,
AttributeError: 'NoneType' object has no attribute 'add_attr'