This is strange, I Just upgraded and am having problems.
I got some new ebooks from Amazon today. I want to strip drm and convert to mobi for my irex. But I get messages about PIDs not benig found. If I try books I have converted in the past then these also fail.
I went back to a version of calibre 8.23 which was about what I was using before and still no joy.
I aso restarted calibre many times reinstalled the plugins nothing has worked. I will now try removing all converted books and see if this fixes my problem.
BTW this was on the MAC OSX version.