I encountered this problem today. There seems to be a whitelist of allowed file types that doesn't include epub. The simplest workaround seems to be using another file sharing method. Another (not tested) is packing your chosen files into a zip archive and sending that. You could also try temporarily changing file extensions to *.jpg, sending them and changing the extensions back.
I encountered this problem today. There seems to be a whitelist of allowed file types that doesn't include epub. The simplest workaround seems to be using another file sharing method. Another (not tested) is packing your chosen files into a zip archive and sending that. You could also try temporarily changing file extensions to *.jpg, sending them and changing the extensions back.
A Google search showed some relevant info, so I'll just link it here in case someone finds it useful. This question is for app developers: https://stackoverflow.com/q/2942454 . And this article is about allowing more file types on a rooted phone: https://htc-one.gadgethacks.com/how-to/bypass-androids-file-type-restrictions-bluetooth-file-sharing-0157237/ .