Hello,
When trying to send a document to my Kobo Aura One, I get the same behavior as exposed in this topic :
https://github.com/koreader/koreader/issues/2540
I'm running under MacOS 10.12.3.
The first guy summarized pretty well the issue:
Steps to reproduce
1. Start wireless server in Calibre. Server starts.
2. Connect Koreader to Calibre wireless. Client says that it is connected.
3. Calibre does not react to established connection, no connected device menus appear, no "On device" column. If you try to do anything related to wireless connection in Calibre (i.e. open "share" menu or try to upload a book), it's UI becomes unresponsive.
Despite this bug, Calibre is a great tool. It's been very practical and user-friendly. Thank you for developing and maintaining it over the years!
Ryt