@BetterRed & @ownedbycats: That were the first things I checked: negative.
I found the cause: its in the PDF file handling.
A working PDF-file has the following ending:
Code:
<</ID[<B43E3B0286664B420FA6AC3FE4CBFF8B><B43E3B0286664B420FA6AC3FE4CBFF8B>]
/Info 1935 0 R
/Root 1937 0 R
/Size 1945>>
startxref
55999427
%%EOF
My failing PDF-file (which is however perfectly genuine) shows:
Code:
<</Size 1127
/ID [(Vؘr„g ‘X%ÃVCÙÂ) (Vؘr„g ‘X%ÃVCÙÂ) ]
/Root 1625 0 R >>
startxref
37312594
%%EOF
Calibre did show as an error "EOFError", so I concluded it was parsing to something it expected, but did not find before hitting %%EOF.
As can be seen, my PDF-file is missing the (optional) entry "/info xxxx x R", so I manually added that and now calibre does not complain anymore.
My PDF-file was generated by using the well-known Poppler tool "pdfunite" (I tried multiple versions and the most recent 23.08.0 one for windows) , which never seems to include the "/info" entry.
First conclusion therefor is that the calibre parsing-tool is expecting something which not necessary needs to be present.
PDF-files are (and will be) a pain in the xxx
