This is a list of major known issues. For the latest list of all issues see the Github Issues page
FolioReader might not work properly on API 21 and 22 Emulator images. As these images have Android System Webview lower than version 44. Devices or Emulator of API 21 and 22 with Google Play Store will be able to run FolioReader without any error after updating Android System Webview to version 44+
From version 0.5.1, Media Overlay would not work as the streamer implementation is not done yet in r2-streamer-kotlin.
From version 0.5.2, TTS is disabled. In previous versions, sentences were formed by changing the DOM structure. To implement TTS without changing DOM would require NLP to extract sentences. As of now, no major reading systems other than Google Play Books implements TTS bug free.