• KOReader version: 20170430
• Device: Android, Kindle

Issue

The reading progress sync feature/plugin stopped working a few weeks ago.
Apparently the built-in sync server at https://vislab.bjmu.edu.cn:7200 does not respond (no browser/telnet connection as well, at least from Poland).
Will it be fixed? Is there another public custom server I can configure?

Steps to reproduce

Progress push/pull request: error msg, that something went wrong.
Logout and then Login or Register attempt: 'Unknown server error'.