Upgrade/Delete Books Issue

Since I upgraded to calibre 0.8.39 this evening, I've had all kinds of strange problems with my kobo interfacing with calibre. Here's a calibre error detail: database disk image is malformed

Traceback (most recent call last):
File "site-packages\calibre\gui2\device.py", line 82, in run
File "site-packages\calibre\gui2\device.py", line 339, in _books
File "site-packages\calibre\devices\kobo\driver.py", line 299, in books
DatabaseError: database disk image is malformed

Anyone have a clue what to do, ebook worms?