LuceVoce

Fix common problems

What to do when the voice sounds robotic, a language has no voice, a book won't open, a scanned PDF is silent or your place doesn't reach another device.

Windows
Yes
Mac
Yes
iPad
Yes
iPhone
Yes
Show steps for

Most problems have a quick fix. Find yours below.

The voice sounds robotic

The natural voices aren't downloaded yet, so your device's own voices are reading. Open the voice picker in a book, or Settings > Voice, and download them: about 410 MB on Mac, iPhone and iPad, about 340 MB on Windows. See Get the natural voices (Kokoro).

  • A voice is listed with "needs the Kokoro download": the same download.
  • A voice is listed with "needs a download": choose Download next to it in the voice list.
  • The download stopped: check your internet connection and choose Try again.

There's no voice for my language

  • "No voices for the chosen languages yet": add a voice for the language in your device's speech settings, or add a Piper voice in Settings > Voice. See Piper voices and voices you add.
  • A book is read with the wrong voice or in the wrong language: check the book's language in Edit information…. Then open Settings > Voice and, under Voice for each language, choose a voice for that language. See Choose a voice.

The highlight is out of step with the voice

  • The text doesn't scroll with the voice: LuceVoce stops following for a few seconds after you scroll by hand. Choose Back to the current position to return to the spoken word. If it never follows, turn on Follow the voice in Settings > Reading.
  • The word highlight runs a little ahead or behind within a sentence: with the natural voices (Kokoro and Piper), LuceVoce works out where each word falls from the sound, so it can be slightly off on some words. Your device's own voices report each word exactly, so choose one of those if you need precise timing.
  • No word is lit at all: check that Highlight the spoken word is on in Settings > Reading.

A book won't open

The book may have copy protection, or the file may be damaged. LuceVoce says which.

  • "This EPUB is protected by DRM and cannot be read" or a similar message: the book is locked by its seller. LuceVoce never removes DRM, so it can't read these books. This covers Kindle, Apple Books, Kobo, Adobe and Audible. Look for a DRM-free copy of the book. See Books protected by DRM.
  • "This PDF is protected by a password": remove the password in the app that made the PDF, then add the PDF again.
  • The book looks faded in the library, with "File missing": its file has moved. Choose Find file and show LuceVoce where the file is now. Your place, notes and bookmarks come back. See Fix a book whose file is missing.
  • A folder scan skipped a book: the report at the end of the scan lists books protected by DRM, formats that are not supported yet and files that could not be read.

A scanned PDF reads nothing

Pages that are only pictures of text need text recognition. LuceVoce does this by itself in the background when the PDF opens, and shows "Reading scanned pages" while it works. Your device needs the book's language for text recognition; the message in the book links to the right setting.

If nothing happens:

  1. Open Settings > Library and check that Read scanned pages with text recognition (OCR) is on.
  2. Close the PDF and open it again.

Windows

Text recognition uses the languages installed in Windows. If the book's language isn't installed, LuceVoce says so. Choose Open Language settings, then in Time & language > Language & region, add the language with its Optical character recognition feature.

Mac

Text recognition is built into macOS and covers many languages. There is nothing to install.

iPhone and iPad

Text recognition is built into the system and covers many languages. There is nothing to install.

My place didn't come across from my other device

Check these in order:

  1. Sync is on on both devices, in Settings > Sync, with the same folder chosen on each. Other devices should list the other device with the time it last saved a place. If it isn't there, its files haven't reached this device yet.
  2. Give your cloud a moment to copy the files. The cloud app has to be running and signed in on both devices: iCloud for Windows, OneDrive, Dropbox, Google Drive or Box on a PC. On a Mac, iPhone and iPad, iCloud Drive has to be on.
  3. The other device paused. Your place is saved when you pause, not while the voice is reading. Pause on the device you read on, or close the book there.
  4. This book is paused. The offer never appears while a book is reading aloud. Pause it, or go back to the library and open the book again.
  5. It is the same book. Two devices match a book by its file, or by its title and author. If the titles differ, edit them with Edit information… so they match.
  6. The setting allows it. Under Another device's reading place, Stay at this device's place never offers another place. Choose Ask each time.
  7. You didn't just choose Stay here. That hides the offer until the other device reads on again.

On an iPhone or iPad, choose a folder in iCloud Drive. OneDrive folders can't be chosen there yet, so a PC and an iPhone have to meet in iCloud Drive, with iCloud for Windows on the PC.

If Settings > Sync shows "Sync could not write to the folder", the folder may have been moved, renamed or taken offline. Choose Change… and pick the folder again.

Related

  • Get the natural voices (Kokoro)Why the natural Kokoro voices are worth the one-time download, how big it is on each device, which languages they read and where to start it.
  • Choose a voiceHow to pick the voice for a book, listen before you choose, set a voice for each language, and have passages in another language read by their own voice.
  • Listen to scanned PDFsHow LuceVoce reads PDF pages that are only pictures with text recognition (OCR), what you need on Windows, and how to turn it off.
  • Books protected by DRMWhy LuceVoce refuses books and documents protected by DRM or a password, how to recognise them, and what you can do to listen to the book instead.
  • Fix a book whose file is missingWhat it means when a book in your library shows File missing, and how to use Find file to show LuceVoce where the book's file is now.
  • Continue reading on another deviceHow to pause a book on one device and pick it up at the same sentence on another, through a folder in your own iCloud Drive, OneDrive or Dropbox.
  • What stays on your deviceLuceVoce has no account, no server of its own and no tracking. This page lists exactly when it goes online, what it sends, and what your sync folder holds.

Last updated 13 November 2026