[BranMakMorn]

Dear all,

I've used Calibre for years, since 2010 in fact, and I never had a problem with it. I now have a very large library of over 7300 books.

A few days back, all of a sudden, Calibre started giving me a strange error when opening books (double clicking on the title) something like "I/O error".

It eventually told me the metadata database was corrupted and that it needed to re-check everything. So it did, taking a pretty long time.

Now, I got a report with LONG list of "Invalid Titles", "Extra titles", "Extra Authors", "Extra Book Formats" and "Unknown Files in Books" (hundreds of entries).

In practical terms, I have 3 different kind of problems:

1) there are many titles which appear in the database but that tells me it cannot find the file, while in fact the PDF file is where it should be (I click "open path" and there it is) OR there are even TWO copies of the same PDF;

2) there are many titles which appear in the database but that tells me it cannot find the file, and in fact the relevant folder has only the "cover" and the "metadata": where the hell did my books go?? (this is what really worries me).

2) there are many books for which I have the PDF in the correct folder, or again sometimes even two files, or two metadata files, (but sometimes the folder has no number in brackets) which do not appear on the database.

[NB these problems do not match exactly with the categories of error above: if it search for titles in the list of "Extra Titles" sometimes they will not appear in the database but will be in the folder, sometimes it will show in the database and also work fine...]

I don't know what to do. I tried to uninstall and reinstall the lastest version, using the old library, but didn't help. I tried to tell calibre to restore database twice, but I always get error messages. Can anyone hand-hold me through this? I am mostly concerned about the many seemingly missing books. As a LAST resort I could explode the calibre library, delete everything but the PDFs and re-add everything in a new fresh installed program, but that would mean having to re-correct everything for over 7000 books. It took me years to populate and keep this library database tidy.

Help please!