step 0 ) Make a backup of you library folder, 'just in case'
http://manual.calibre-ebook.com/faq....libre-is-blank Imagine the word 'Partially" being shown there.
If the rebuild fails to find all (or you have already tried this)
Alternately
Use Calibre to Move <<This keeps as much as possible of what you do have
the books (w/formats) it KNOWS about to a new Library folder using this procedure
step
0 ) Make a backup of you library folder, 'just in case'
1)Use the Library icon menu to Create a new Library (location)
using the existing structure (tick)
2) in the original:
Search: formats:true
2b) Select all (ctrl-A): right-click in the list:
copy to Library: delete after copy
What now remains (in the OLD Library folder) is what Calibre forgot about due to DB damage
to recover this, you will now use the normal ADD (books).
3)The second item On the Add Books Icon pulldown menu (matches a normally Library layout). Point that to the Main (broken) Library folder (The one with all the Author folders)
If all that succeeds, you can just discard the backup of the damaged Library, and clean out the OLD Library remains