If you're trying to train your Personal Style and you're getting an error that your catalog cannot be accessed, please double check the following:
If your catalog is stored on a network drive (NAS), it must first be copied onto your computer or an external drive.
If you're using a cloud based storage system such as iCloud or OneDrive, ensure that you have all the files related to your catalog downloaded to your computer.
Safely disconnect and reconnect any of your external drives that your catalogs are stored on.
Ensure that your Catalogs are working and up to date with the latest Lightroom version.
If you've gone through the above steps and your catalog still cannot be accessed, you should clear your cache and restart Narrative.
You can clear your cache by clicking Help > Troubleshooting > Delete App Cache
Please note, this will also reset your preferences so you might want to jump back into that menu and re-apply any preferences you had selected.
If you're experiencing any other issues or the article above hasn't resolved your issue, please contact support via the chat bubble in the bottom right corner.