Cannot add books to Calibre

[Gilles R]

I have about 10000 books in Calibre and have been using it for several years. I have a MAC.
Recently, I keep receiving the following error:

calibre, version 2.12.0
ERROR: Errors while adding: Failed to add any books, click "Show details" for more information

----------------------------------------------------------------------
Failed to add the book: Special Ops
 /Users/Joseph/Documents/Digital Editions/Special_Ops.epub
With error:
Traceback (most recent call last):
  File "site-packages/calibre/gui2/add.py", line 366, in add_book
  File "site-packages/calibre/db/legacy.py", line 211, in create_book_entry
  File "site-packages/calibre/db/cache.py", line 57, in call_func_with_lock
  File "site-packages/calibre/db/cache.py", line 1481, in create_book_entry
  File "site-packages/calibre/db/cache.py", line 1218, in set_metadata
  File "site-packages/calibre/db/cache.py", line 1045, in update_path
  File "site-packages/calibre/db/backend.py", line 1475, in update_path
  File "lib/python2.7/os.py", line 157, in makedirs
OSError: [Errno 13] Permission denied: '/Users/Joseph/Calibre Library/W.E.B. Griffin/Special Ops (10099)'

Please advise and Thank you

Gilles

[Kovid Goyal (kovid)]

See
http://manual.calibre-ebook.com/faq.html#i-am-getting-a-permission-denied-error

 status invalid