Hi @Yanan_Zhao,
This is a data integrity problem. The genre_id
for those files will need to be set to something that exists in the genres
table; you can get the list of items (and see their IDs) by going to Settings > Workflow > Components. If you hover over the “Edit” link for one of the entries in the list you’ll see the end of the URL containing genreId=xyz
, where xyz
is a number. That’ll tell you the genre ID for that entry.
As for how the data integrity problem arose, it’s probably related to the lack of a warning/check when deleting a component. This is already filed in our issue tracker for improvement; see Prevent deletion of active genres/components · Issue #3899 · pkp/pkp-lib · GitHub for details.
Regards,
Alec Smecher
Public Knowledge Project Team