Comment 1 for bug 1711272

The error you mention comes from a corrupted PDF file. As far as I know,
all such errors are already ignored, they simply cause reading metadata
from the PDF file in question to fail. Indeed, reading PDF metadata
happens via a separate worker process, so even if it is killed, it does
not matter. So if calibredb add finished, it most likely added all your
books. Check the exit code of the calibredb process.

 status invalid