I've not seen this error discussed in other posts. I don't think the Calibre software is causing it, but don't know where else to seek help.
On my wife's gen 4 iPad mini, when clicking on "Download" for a book, it tries to download <book_title>.epub.txt which of course doesn't exist. The server is running on Windows 10 Pro 64bit. Rebooting the iPad doesn't help, nor does rebooting the server.
She can go to my backup server running Linux Mint Cinnamon 19.3 and the download works fine. My older iPad mini works fine to both servers.
I see similar problems when using the Edge browser on my Windows Surface tablet, but the error reads "couldn't download - no permissions". Googling this error yields many different "fixes", none of which helped. Logging into the Surface tablet with a different user works fine!
Using Calibre release 5.17, but it has happened at various times with earlier releases. Any clues?
