Download Metadata then Error 32

[Magnus]

Added new books. After downloading metadata and selecting cover I either click OK to exit metadata, or I click the forward arrow to move onto the next book to add metadata.

When I do this often Calibre pops-up an error window ...

calibre, version 2.77.0
ERROR: Unhandled exception: error: (32, 'DeleteFile', 'The process cannot access the file because it is being used by another process.')

calibre 2.77 [64bit] embedded-python: True is64bit: True
Windows-8-6.2.9200 Windows ('64bit', 'WindowsPE')
('Windows', '8', '6.2.9200')
Python 2.7.9
Windows: ('8', '6.2.9200', '', 'Multiprocessor Free')
Successfully initialized third party plugins: DeDRM (6, 3, 6) && K4PC, K4Mac, Kindle Mobi and Topaz DeDRM (0, 4, 2) && Inept Epub DeDRM (0, 1, 7) && Inept PDF DeDRM (0, 1, 4) && Ignoble Epub DeDRM (0, 1, 6) && eReader PDB 2 PML (0, 0, 6)
Traceback (most recent call last):
File "site-packages\calibre\gui2\metadata\single.py", line 622, in next_clicked
File "site-packages\calibre\gui2\metadata\single.py", line 554, in apply_changes
File "site-packages\calibre\gui2\metadata\basic_widgets.py", line 219, in commit
File "site-packages\calibre\db\legacy.py", line 816, in func
File "site-packages\calibre\db\cache.py", line 61, in call_func_with_lock
File "site-packages\calibre\db\cache.py", line 1074, in set_field
File "site-packages\calibre\db\cache.py", line 1088, in update_path
File "site-packages\calibre\db\backend.py", line 1566, in update_path
File "site-packages\calibre\utils\filenames.py", line 461, in delete_originals
error: (32, 'DeleteFile', 'The process cannot access the file because it is being used by another process.')

Any ideas? Usually clicking OK or forward error again allows Calibre to move on.

[kovidgoyal]

Some other process on your computer is accessing the files int he calibre library at the same time as calibre. Common culprits are an overly aggressive antivirus program or putting your calibre library in a "clod" folder like dropbox.