[DNSB]

calibre does not have a "valid purchase" tag.

Are you using a cloud backup with your calibre library? If so, make sure it is only running when calibre isn't. Otherwise, you may have an issue with your hard drive. Does Drive Repair show any issues when you ran it?

If you can do a screen shot of the results from running Check library, you can use the paperclip/manage attachments tool to attach them to a message.

You might also want to try running calibre in debug mode (Preferences => Restart in debug mode), running Check library and then posting the log file though I'm not certain if debug mode will capture the check library events. Please use code tags around the text and then spoiler tags around the code tags as in the sample below:

Spoiler:

ApplicationPaletteChange event ignored
Using calibre Qt style: True
ApplicationPaletteChange event received
EpubMerge: DEBUG: 2023-08-15 08:39:53,054: calibre_plugins.epubmerge.epubmerge_plugin(156): macmenuhack file_path:C:\Users\dbowe\AppData\Roaming\calibre\plugins\fanficfare_macmenuhack.txt
FFF: DEBUG: 2023-08-15 08:39:53,065: calibre_plugins.fanficfare_plugin.fff_plugin(215): Plugin FanFicFare macmenuhack file_path:C:\Users\dbowe\AppData\Roaming\calibre\plugins\fanficfare_macmenuhack.txt
calibre Debug log
calibre 6.24  embedded-python: True
Windows-10-10.0.22621-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.22621')
Python 3.10.1
Windows: ('10', '10.0.22621', 'SP0', 'Multiprocessor Free')
Interface language: en_CA
Successfully initialized third party plugins: DeACSM (0, 0, 16) && Gather KFX-ZIP (from KFX Input) (2, 3, 0) && DeDRM (10, 0, 9) && AZW6 Image Merge (1, 1, 1) && Package KFX (from KFX Input) (2, 3, 0) && Annotations (1, 17, 13) && Count Pages (1, 13, 0) && Diaps Editing Toolbag (0, 4, 0) && EpubCheck (0, 2, 5) && EpubMerge (2, 16, 0) && EpubSplit (3, 6, 0) && FanFicFare (4, 25, 0) && Find Duplicates (1, 10, 8) && Job Spy (1, 0, 239) && KFX metadata reader (from KFX Input) (2, 3, 0) && KFX Input (2, 3, 0) && Set KFX metadata (from KFX Output) (2, 2, 0) && KFX Output (2, 2, 0) && Kindle hi-res covers (0, 5, 0) && KindleUnpack - The Plugin (0, 83, 1) && Kobo Books (1, 10, 2) && Kobo Utilities (2, 16, 10) && KoboTouchExtended (3, 6, 4) && Modify ePub (1, 8, 1) && Obok DeDRM (10, 0, 9) && Open With (1, 8, 1) && Quality Check (1, 13, 6) && Resize Cover (1, 2, 0) && ScrambleEbook (0, 6, 0) && SmartEject (2, 5, 0) && Smashwords Metadata (1, 0, 2)
calibre 6.24  embedded-python: True
Windows-10-10.0.22621-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.22621')
Python 3.10.1
Windows: ('10', '10.0.22621', 'SP0', 'Multiprocessor Free')
Interface language: en_CA
Successfully initialized third party plugins: DeACSM (0, 0, 16) && Gather KFX-ZIP (from KFX Input) (2, 3, 0) && DeDRM (10, 0, 9) && AZW6 Image Merge (1, 1, 1) && Package KFX (from KFX Input) (2, 3, 0) && Annotations (1, 17, 13) && Count Pages (1, 13, 0) && Diaps Editing Toolbag (0, 4, 0) && EpubCheck (0, 2, 5) && EpubMerge (2, 16, 0) && EpubSplit (3, 6, 0) && FanFicFare (4, 25, 0) && Find Duplicates (1, 10, 8) && Job Spy (1, 0, 239) && KFX metadata reader (from KFX Input) (2, 3, 0) && KFX Input (2, 3, 0) && Set KFX metadata (from KFX Output) (2, 2, 0) && KFX Output (2, 2, 0) && Kindle hi-res covers (0, 5, 0) && KindleUnpack - The Plugin (0, 83, 1) && Kobo Books (1, 10, 2) && Kobo Utilities (2, 16, 10) && KoboTouchExtended (3, 6, 4) && Modify ePub (1, 8, 1) && Obok DeDRM (10, 0, 9) && Open With (1, 8, 1) && Quality Check (1, 13, 6) && Resize Cover (1, 2, 0) && ScrambleEbook (0, 6, 0) && SmartEject (2, 5, 0) && Smashwords Metadata (1, 0, 2)
QPA platform: windows
devicePixelRatio: 1.0
logicalDpi: 96.0 x 96.0
physicalDpi: 81.55183946488295 x 81.64285714285714
[0.00] Starting up...
[0.00] Showing splash screen...
[0.16] splash screen shown
[0.16] Initializing db...
[0.16] db initialized
[0.16] Constructing main UI...
DEBUG:    0.0 Annotations plugin: Error loading libiMobileDevice. This hasn't worked for a while, and is blacklisted in calibre v3.
DEBUG:    0.0 Annotations plugin: Error is:  No module named 'calibre.devices.idevice'
DEBUG:    0.0 Annotations::reader_app_support.py - loading translations
DEBUG:    0.0 Annotations::common_utils.py - loading translations
DEBUG:    0.0 Annotations::appearance.py - loading translations
DEBUG:    0.0 Annotations::config.py - loading translations
DEBUG:    0.0 Annotations::annotated_books.py - loading translations
DEBUG:    0.0 Annotations::action.py - loading translations
DEBUG:    0.0 Kobo Utilities Configuration - CreateNewCustomColumn is supported
DEBUG:    0.0 KoboUtilites::action.py - loading translations
DEBUG:    0.0 KoboUtilites::dialogs.py - loading translations
DEBUG:    0.0 KoboUtilites::action.py - loading translations
DEBUG:    0.0 obok::utilities.py - loading translations
DEBUG:    0.0 obok::dialogs.py - loading translations
DEBUG:    0.0 obok::config.py - loading translations
DEBUG:    0.0 obok::action_err.py - loading translations
qt.webengine.QWebEngineView OK
Job Spy has begun initialization...
Calibre, and hence Job Spy, was gracefully shut down last time?  True
Last time daemon started:  never
Last time daemon failed:  never
Total daemon starts inception_to_date:  0
Total daemon failures inception-to-date:  0
JS: ===>>> change_gui_alternating_row_colors()
Job Spy has finished initialization...
DEBUG:    0.8 No Kobo Touch, Glo or Mini appears to be connected
DEBUG:    0.8 rebuild_menus - self.supports_ratings=None, self.supports_tiles=None
DEBUG:    0.8 KoboUtilities:set_toolbar_button_tooltip - start: text='None'
DEBUG:    0.8 KoboUtilities:set_toolbar_button_tooltip - setting to text='Utilities to use with Kobo ereaders

Driver: KoboTouch'
[1.62] main UI initialized...
[1.62] Hiding splash screen
Starting QuickView