Unable to open database

[loatoday]

I just upgraded, and now I can't open my database:

calibre, version 3.24.2
Corrupted database: The library database at C:\Users\Walt\Documents\Calibre Library appears to be corrupted. Do you want calibre to try and rebuild it automatically? The rebuild may not be completely successful. If you say No, a new empty calibre library will be created.

Traceback (most recent call last):
File "site-packages\calibre\gui2\main.py", line 312, in initialize_db
File "site-packages\calibre\db\legacy.py", line 81, in __init__
File "site-packages\calibre\db\legacy.py", line 48, in create_backend
File "site-packages\calibre\db\backend.py", line 378, in __init__
File "site-packages\calibre\db\backend.py", line 1123, in fget
File "site-packages\calibre\db\backend.py", line 836, in conn
File "site-packages\calibre\db\backend.py", line 267, in __init__
CantOpenError: CantOpenError: unable to open database file

If I click Yes I get:

calibre, version 3.24.2
ERROR: Failed to repair library: Restoring database failed, click Show details to see details

Traceback (most recent call last):
File "site-packages\calibre\db\restore.py", line 123, in run
File "site-packages\calibre\db\restore.py", line 239, in create_cc_metadata
File "site-packages\calibre\db\restore.py", line 29, in __init__
File "site-packages\calibre\db\backend.py", line 378, in __init__
File "site-packages\calibre\db\backend.py", line 1123, in fget
File "site-packages\calibre\db\backend.py", line 836, in conn
File "site-packages\calibre\db\backend.py", line 267, in __init__
CantOpenError: CantOpenError: unable to open database file

[loatoday]

By the way ... I don't really care about what I've loaded into Calibre before. I'm happy to start from scratch.

[loatoday]

The application was being blocked by my anti-virus. Once I unblocked it, everything started to work.