This is new for me because I had Ubooquity on my old install (I had to reinstall Windows 10) and it worked perfectly.
I have a massive 2TB folder of books. Ubooquity stops scanning and adding books when it gets to the letter "E," so only roughly half my books are in the library. It doesn't add any of those books to the library and I can't search for them inside Ubooquity, either.
Customer support service by UserEcho