[PsiHazard]

First, I apologize if this is in the wrong place or an issue that's been covered already; I'm new to the board and did try to search, but TBH I wasn't really sure how to phrase my questions.

I'm seeing a variety of formats for most of the entries in my Calibre library that do not exist in the actual file folder for that entry. For example, for Title A, .EPUB, .AZ3, ORIGINAL_EPUB, and ORIGINAL_AZ3 are shown in the Information (I) pane, and in the information listed in the rightmost panel of Calibre's default layout. However, the actual folder (accessed via "O" or through the file system) may contain only some or even none of those files/formats. Typically, the formats starting with ORIGINAL_ won't be in the folder.

I don't know when this happened or what may have caused it. The library has moved around a bit and seen some changes over the years. I'm not brand-new to Calibre, but I wouldn't consider myself an advanced user either. I probably attempted something odd involving file conversion at some point to create the "ghost" formats, but I have no idea why some folders are completely empty.

My questions are these:

First, where is the information on which formats are available for a given entry in the library stored, and can that be refreshed/rebuilt/recreated? If so, what is the preferred or recommended method?

Second, is there a way to determine which of my library entries have no ebook files at all, despite showing several available formats in Information?

Ideally, any solution would be able to applied to the library as a whole rather than manually editing each individual library entry

Thanks for reading!