I use Windows Search from Windows File Explorer 'a lot', sometimes dozens of times a day. Calibre is usually running because if the search finds files in a calibre library I use the Drop Search Results plugin to "Mark the books", and/or create "Reading Lists".
I suspect this is something to do with the recent folder locking changes. Here's why:
- I just did a search for a word (Gorbachev) I knew would be found in some of the DOCX, PDF and EPUB format files in my Books library (there were 53 of them).
- With the Windows search results widow open and visible, I located and selected the first book in the list (Book#1168, Garton Ash's "History of the Present").
- Pressed F2 on the Title cell and added "in September" to the title, saw the file name in the Windows Search results window change accordingly.
- Did a Library Check -- no problems.
- Opened the book folder, pressed F2 on the Title cell removed "in September', and saw the Book folder name and contents change accordingly, as did the Search results window.
- Did a Library check -- no problems.
- Added a 'data' folder to the Garton Ash book and copied James Baker's "Why Gorbachev Mattered" essay onto it and repeated the above - with no problems - the 'data' folder and its content were preserved
Bonus, Windows Search found the Baker essay in Book 1168's 'data' folder.
The folder locking changes were introduced in version 6.20. for an unrelated reason I have decided to freeze my calibre installation at version 6.18.1.
BR